Highly disappointed!

[DrewQ45]

I'm sofa king disappointed!

Got together with Slim, aka 450zxtt on here. We swopped out my bad differential for one I had picked up about a month ago. For those of you that don't know him, he only has the baddest Z out there into which he dropped a VH45, mated it to the 5 speed and twin turboed it to boot. Here's his website if any newbies want to check out the car...

http://www.freewebs.com/axepower/index.htm

...anyway, back to the diff job. It was a job I would have done myself, but lately I haven't had the patience to sit under the Q for hours, plus the thing weighs like 80 lbs. I took the opportunity to change the oil and install some rear subframe spacers while the car was up on stands.

Slim is a hilarious guy! At one point while I was straining to hold the diff in place while he caught the nuts, he mentioned that my arm was trembling like a baby chipmunk just entering this cold world. It was all I could do to not drop the pumpkin on his head.... .... my jovial state was short lived however. When we dropped the old girl back on the pavement and took her for a test drive, the rear end was singing twice as loud as the one I had just removed. Well, Slim honored his part of the deal so I paid him for his assistance. So here I am, out the money I paid Slim and now I have a diff in worse shape than the one I took out. The thing is so loud my ears were ringing when I got home. It didn't help that I was cussing at the top of my voice with the windows up. Anyway, suffice to say, I'm looking for a diff in known good working order. Preferably in or near the ATL area.

The Q sits for now till one is found....guess she needed the rest. I do need one fast though.

...Drew.....

[oldmako]

I am curious as to what led you to believe that your diff was wasted. What types of noise and when??

Just curious because the BB (Ebony Beeotch) has been singing a bit, but I can't pin down the source of the song. My cramped and dirty shop has but one poorly trained and very lazy mechanic. He has few tools, and even fewer abilities. Nuts and bolts is one thing, but diagnostics is another.

[sijoko]

I'm sofa king disappointed!

Got together with Slim, aka 450zxtt on here. We swopped out my bad differential for one I had picked up about a month ago. For those of you that don't know him, he only has the baddest Z out there into which he dropped a VH45, mated it to the 5 speed and twin turboed it to boot. Here's his website if any newbies want to check out the car...

http://www.freewebs.com/axepower/index.htm

...anyway, back to the diff job. It was a job I would have done myself, but lately I haven't had the patience to sit under the Q for hours, plus the thing weighs like 80 lbs. I took the opportunity to change the oil and install some rear subframe spacers while the car was up on stands.

Slim is a hilarious guy! At one point while I was straining to hold the diff in place while he caught the nuts, he mentioned that my arm was trembling like a baby chipmunk just entering this cold world. It was all I could do to not drop the pumpkin on his head.... .... my jovial state was short lived however. When we dropped the old girl back on the pavement and took her for a test drive, the rear end was singing twice as loud as the one I had just removed. Well, Slim honored his part of the deal so I paid him for his assistance. So here I am, out the money I paid Slim and now I have a diff in worse shape than the one I took out. The thing is so loud my ears were ringing when I got home. It didn't help that I was cussing at the top of my voice with the windows up. Anyway, suffice to say, I'm looking for a diff in known good working order. Preferably in or near the ATL area.

The Q sits for now till one is found....guess she needed the rest. I do need one fast though.

...Drew.....

I feel your pain. I went thru a similar ordeal with my 95 Q. I was visiting my Mom in the Atlanta area. The rear end was starting to get very noisey and I found one thru car-part.com that the salvage yard said had only 80k miles. The price was good at $150 so I jumped at it. I had to go to New York for classes in a few days so I began the process of removing the old and replacing it with the one from the yard. I finished just in time to leave for New York. When I took the car for a drive, the noise was the same or maybe worse. I was fuming! But I had to leave the next day and I had to deal with it.

Fast forward, to last month. I was in the Atlanta area again and decided to see if I can find a diff in better condition. Again, back to car-part.com. This time, the diff that I found had a supposed 11 miles on it. I thought to myself, "Right". But I went to check it out and it looked like it was a very low mileage unit. It was also very tight so I paid the dude $200 and went home with the diff. I got home and inspected the fluid. It was honey golden which was a very good sign. So, it went in the car and I am very happy. I've put over 3k miles on it and it is utterly noiseless.

So the moral of the story.... don't give up. Keep looking for a low mileage unit. You'll come across one in due time.

[DrewQ45]

I am curious as to what led you to believe that your diff was wasted. What types of noise and when??

Just curious because the BB (Ebony Beeotch) has been singing a bit, but I can't pin it down.

Well, it started with a whining noise that could almost be mistaken for the transmission not shifting to a higher gear, only that the transmission shifts fine and the rpms prove it. Shift into nuetral while at speed and it's still the same. Once wheel bearings are eliminated, you pretty much know it's the diff. I also put the car on stands and ran it on cruise control while underneath it. Many of you may be experiencing the beginning of diff failure, but will not notice the subtle increases in diff noise till it becomes too loud to ignore.

[DrewQ45]

Yeah.... I wish there was a way to bench test before installing. All it would take is a hookup to a rotating shaft of some kind...hmmm.

[oldmako]

Did you look for a new or reman unit? Cuzminehasawhine. I tried shifting into neutral while trouble shooting and the noise was still....noisy.

[sijoko]

Yeah.... I wish there was a way to bench test before installing. All it would take is a hookup to a rotating shaft of some kind...hmmm.

From my experience, the fresher the diff: the tighter the tolerances. Just grab the output flanges and twist them in opposite directions. A worn diff will have a lot of slack in it. The one that I finally got was super tight.

[DrewQ45]

From my experience, the fresher the diff: the tighter the tolerances. Just grab the output flanges and twist them in opposite directions. A worn diff will have a lot of slack in it. The one that I finally got was super tight.

Not necessarily true... the one I put in was tight. As a matter of fact, when turning the main shaft, it felt a bit notchy so I took it to a Nissan dealer for rebuild... the service mgr comes out to the car (I had the 'new' diff sitting in the trunk), he turns the shaft, said it felt great and it didnt need to be rebuilt. Wish I had gone with my instincts.

[sijoko]

Not necessarily true... the one I put in was tight. As a matter of fact, when turning the main shaft, it felt a bit notchy so I took it to a Nissan dealer for rebuild... the service mgr comes out to the car (I had the 'new' diff sitting in the trunk), he turns the shaft, said it felt great and it didnt need to be rebuilt. Wish I had gone with my instincts.

I'm talking about the output flanges where the half shafts connect. If you twist them in opposite directions, there should be very little free play. As far as the main shaft flange, if you feel any notchiness then it is a no-go. The culprit is the bearing at the nose of the diff. Once this wears out, the whole alignment of the gears is thrown and you get an unbearable whine. Actually, mine was more like a howl. Either way, it drove me crazy.

[Q45tech]

The nose bearing wears out due to not keeping the drive shaft in perfect balance. Which is one of the potential costs of a one piece driveshaft - lower diff life.

Not perioducally MEASURING and correcting oem driveshaft can do the same thing just takes longer.

Hopefully you see correlation.

[maxnix]

Got together with Slim, aka 450zxtt on here.

Not to hijack, but get Slim to post an account of his TT here as he may have the best (and only) TT VH45DE. Miles driven, maintenance history, operational notes would be interesting. I bet it's not a daily driver, and I wonder how clutch and transmission are lasting. 2nd gear synchro gone yet?

[elwesso]

Not to hijack, but get Slim to post an account of his TT here as he may have the best (and only) TT VH45DE. Miles driven, maintenance history, operational notes would be interesting. I bet it's not a daily driver, and I wonder how clutch and transmission are lasting. 2nd gear synchro gone yet?

I just talked to Slim a few days ago.. Actually, when Drew was in the shop with him..

The car IS a daily driver.. Basically from what I know the JWT programming is really rich so he says the plugs foul easily if its babied around... I think he said he's put somewhere on the order of 10-20k miles in the last few years.. He just replaced the clutch, which this whole time was the same clutch he had on his 600HP V6 twin turbo (just took it off and slapped it on the V8)

[DrewQ45]

I'm talking about the output flanges where the half shafts connect. If you twist them in opposite directions, there should be very little free play. As far as the main shaft flange, if you feel any notchiness then it is a no-go. The culprit is the bearing at the nose of the diff. Once this wears out, the whole alignment of the gears is thrown and you get an unbearable whine. Actually, mine was more like a howl. Either way, it drove me crazy.

You are exactly right in everything you say.

[DrewQ45]

I just talked to Slim a few days ago.. Actually, when Drew was in the shop with him..

The car IS a daily driver.. Basically from what I know the JWT programming is really rich so he says the plugs foul easily if its babied around... I think he said he's put somewhere on the order of 10-20k miles in the last few years.. He just replaced the clutch, which this whole time was the same clutch he had on his 600HP V6 twin turbo (just took it off and slapped it on the V8)

Yeah...he drives it daily.... said he was racing motorcycles with it the day before and hanging pretty well with them.

[DrewQ45]

The nose bearing wears out due to not keeping the drive shaft in perfect balance. Which is one of the potential costs of a one piece driveshaft - lower diff life.

Not perioducally MEASURING and correcting oem driveshaft can do the same thing just takes longer.

Hopefully you see correlation.

You are right tech, it did occur to me previously that the nose bearing wore out when I had drive shaft issues. During transmission replacment, a mechanic had messed with the bolts on the rubber disc of the shaft and threw it out of balance... I drove around that way for about a year until I finally replaced it with a 94' shaft.

Yesterday I pulled a diff out of 94' active Q. The nose bearing felt smooth as silk and the fluid ran out with a nice golden color so I'm hoping my troubles are over. Won't be paying anyone this time... I'm throwing it in myself. Already got the bad one out and have the new diff filled with lucas gear oil. Just one thing stumping me.... the active comes with TCS and the diff has two sensors, one on each output shaft. The wires coming from the sensors converge into a single plug. My old diff is non TCS and has a single sensor up near the nose where the input shaft is located. The active diff's plug is twice the size of my old diff's. I'm wondering if I should just strip the wires coming from both sensors and connect in parallel to my old plug or just install the old plug, sensor and all on one side of the output shaft, leaving the other not connected. Wonder if this would affect anything? THoughts? Need pics?

...Drew...

[Q45tech]

It's been discussed since NICO began that you cannot use a TCS/Active diff on a a non TCS/Active Q [or converse] because of the differences in lengths of input/output tone wheels/shafts without major internal swaps of components.

Even considering it especially after you have removed old unit shows you have not sudied the thousands of previous posts.

Obviously the rpm signal from the input shaft tone wheel will be 3.538 times higher than the ouput signal from output tone wheels so the ABS system would think the rear tires rear turning at 1/3.538 the rate of the front tires.

[maxnix]

It's been discussed since NICO began that you cannot use a TCS/Active diff on a a non TCS/Active Q [or converse] because of the differences in lengths of input/output tone wheels/shafts without major internal swaps of components.

Even considering it especially after you have removed old unit shows you have not sudied the thousands of previous posts.

Ooooops! Maybe some active/TCS owner will take it off your hands.

So who's left from the originals of even just this version of the board? AZHitman, Q45tech, 1990Q45, SZhosain, TexasOil, 1992Q45, a couple of others, maybe........

[thejapino]

The last time I installed subframe spacers in my car, the rear-end made more noise than before. It was the same diff, just noisier. The spacers transmit more noise/vibration from the diff into the cabin.

Also, what subframe spacers did you use? I've used Peak poly and was happy with the results. I've ridden in cars with aluminum spacers and you could definately tell.

[DrewQ45]

It's been discussed since NICO began that you cannot use a TCS/Active diff on a a non TCS/Active Q [or converse] because of the differences in lengths of input/output tone wheels/shafts without major internal swaps of components.

Even considering it especially after you have removed old unit shows you have not sudied the thousands of previous posts.

Obviously the rpm signal from the input shaft tone wheel will be 3.538 times higher than the ouput signal from output tone wheels so the ABS system would think the rear tires rear turning at 1/3.538 the rate of the front tires.

Okay, my disappointment level just jumped up ten more notches. Are you kidding me?

Alright...I performed quite a few searches after reading your post. I don't see anything regarding different shaft lengths for any G50 diff, active/tcs or not. I'll let you know for sure because I will be trying it anyway...nothing to lose at this point. If it doesn't work... chalk one more up for knowledge gained at another's expense.

With regards to the input signal being different.... sounds correct. What you say makes sense as the output shafts are larger than the input. What exactly would that affect though... I know ABS would be thrown off, but would I have speedo issues too? I can live without ABS and even bad speedo reading until I can get the proper rear end in. I just need it to bolt up and run.

Here are the discussions I found... some describe the ABS issue but nothing regarding shaft lengths... well between G50s anyway.

zerothread?id=209136

zerothread?id=122453

zerothread?id=167471
Modified by DrewQ45 at 11:12 PM 4/13/2008

[Q45tech]

I wouldn't waste my time even trying, as we have seen the hack jobs before.

I remember discussing at length in 1999 and 2002. Can you not measure/see the differences between the 2 diffs............there maybe enough play in your drive shaft to jam it in?

[sijoko]

Okay, my disappointment level just jumped up ten more notches. Are you kidding me?

Alright...I performed quite a few searches after reading your post. I don't see anything regarding different shaft lengths for any G50 diff, active/tcs or not. I'll let you know for sure because I will be trying it anyway...nothing to lose at this point. If it doesn't work... chalk one more up for knowledge gained at another's expense.

With regards to the input signal being different.... sounds correct. What you say makes sense as the output shafts are larger than the input. What exactly would that affect though... I know ABS would be thrown off, but would I have speedo issues too? I can live without ABS and even bad speedo reading until I can get the proper rear end in. I just need it to bolt up and run.

Here are the discussions I found... some describe the ABS issue but nothing regarding shaft lengths... well between G50s anyway.

zerothread?id=209136

zerothread?id=122453

zerothread?id=167471

Modified by DrewQ45 at 11:12 PM 4/13/2008

If the diff doesn't work out for you, I might be willing to take it off your hands. I would like to buy a spare for my 95 Q. I'll be back in Atlanta sometime in the next few months. Let me know. - Siju

[DrewQ45]

I wouldn't waste my time even trying, as we gave seen the hack jobs before.

I remember discussing at length in 1999 and 2002. Can you not measure/see the differences between the 2 diffs............there maybe enough play in your drive shaft to jam it in?

Won't be much of a waste of time... the diff is already in postion sitting on a jack under the car. Just needs to be fitted up. I would measure if I had a diff to measure against. I took the latest bad diff back for a refund and my original diff is in pieces. You may remember you and I having discussion about 94' driveshafts not working in 90-93 with regard to length... well I did get one to work without issue so I'm hoping that's an indicator here. Then again...maybe you meant the 'A'... Was TCS standard after 93?

[ddrumman]

I looked into my archives and this is what I found. I don't know if it'll help you.

DIFFERENTIAL

16120 Diff Model Number q45tech Diff or diff gear set? Are you trying to replace a bad diff? The 300Zx units had a 4 channel sensor ABS vs. 90-93 Q 3 channel [rear sensed at input shaft of differential] unless you had traction control then a 4 channel system . The "R200" differential generally was not found with your 3.538 Q ratio in a 300zx which were 3.90 and 4.083 in 90-96 series......most 6 cylinders tt automatics needed the higher ratio to produce good acceleration with the RE4R03A automatic transmission [very rare].

5382 Rear diff. fluid? Synthetic [all ATF is synthetic since it does not occur naturally but must be man made as opposed to motor oil which is largely a part of a natural petroleum product]. Mobil 1 syn ATF will stand higher temperatures for longer intervals than basic generic Dexron spec ATF.....the problem is Dexron spec is a minimum so you don't know which brands are better you cannot always rely on price because of marketing costs to find a better product. The solution is to never let the transmission heat up the fluid beyond 174F and it will last longer. The factory has a conflict in that people complain about cold start up shift quality not how soon a trans fails after warranty so they heat the fluid in the radiator exchanger to smooth things out faster, the problem in the summer is you can cool the fluid below the water temperature [200F] only heat it. Don't think that shifting to Mobil 1 will cure all the heat problems just the fluid will last longer but it still get dirty so you must still flush at 30,000 miles.

The diff change is expensive depending upon where you get the ring and pinion gear say $1500-2500. There are trade off in everything...a lot of money for 0.5 sec improvement but it would yield the same results as adding 40-50 HP or removing 500 lbs.!

Be careful of the differential fluid, the racers use the newer syn version to lower friction, but we are a little scared of it in a long term car. I would use stock fluid and add a tube of max pressure additive and change every 30,000 miles. The viscious LSD is sealed so you don't have to use special LSD fluids/additives. I use 45/45 mixture of stock/Mobil 1 syn diff fluid and 10% additive for 208,000 miles.

Never seen a Q/J differential fail without warning, the noise and whining gets deafening long before. Now abused transmissions are another matter they usually have warned you by the fluid smelling burnt and turning brown......unless you're like me and change it so often it doesn't have a chance to degrade in appearance then sometime after 150,000-200,000 miles you can have an instant failure due to metal fatigue.

[DrewQ45]

I looked into my archives and this is what I found. I don't know if it'll help you.

DIFFERENTIAL

16120 Diff Model Number q45tech Diff or diff gear set? Are you trying to replace a bad diff? The 300Zx units had a 4 channel sensor ABS vs. 90-93 Q 3 channel [rear sensed at input shaft of differential] unless you had traction control then a 4 channel system . The "R200" differential generally was not found with your 3.538 Q ratio in a 300zx which were 3.90 and 4.083 in 90-96 series......most 6 cylinders tt automatics needed the higher ratio to produce good acceleration with the RE4R03A automatic transmission [very rare].

Yeah...I think I saw that somewhere but I can't really apply it to my situation. I'll know for sure tonight when I try to bolt up the rear end.

Thanks for the effort though.

[DrewQ45]

If the diff doesn't work out for you, I might be willing to take it off your hands. I would like to buy a spare for my 95 Q. I'll be back in Atlanta sometime in the next few months. Let me know. - Siju

Even if it does work, I'll probably be looking around for another while I run this one temporarily. Hopefully I'll have my hands on a good 90-93 non-tcs by then.

[szh]

So who's left from the originals of even just this version of the board? AZHitman, Q45tech, 1990Q45, SZhosain, TexasOil, 1992Q45, a couple of others, maybe........

[threadjack]

Yes ... there are a few more around though!

[/threadjack]

Seriously, DrewQ45, I hope you do find the non-active diff for your car. Would hate to see another first-gen Q drop out of use ...

Z

[DrewQ45]

[threadjack]

Yes ... there are a few more around though!

[/threadjack]

Seriously, DrewQ45, I hope you do find the non-active diff for your car. Would hate to see another first-gen Q drop out of use ...

Z

Oh hell no! She's just resting for a min.

[kwjennings]

I have a '93 Q45 with TCS which I have owned since new. It has 193,000 kms on it. The car pretty much looks and runs like new ,however the differential is noisy and I am looking to replace it or rebuild the unit in the car.

Does anyone have a used or overhauled TCS dif?

Does anyone have any advice on how I should proceed? Should I take the exitsting diff to a shop & have new bearings, seal etc put in it?

Ken in Toronto 416 570-4957 cell

[DrewQ45]

I have a '93 Q45 with TCS which I have owned since new. It has 193,000 kms on it. The car pretty much looks and runs like new ,however the differential is noisy and I am looking to replace it or rebuild the unit in the car.

Does anyone have a used or overhauled TCS dif?

Does anyone have any advice on how I should proceed? Should I take the exitsting diff to a shop & have new bearings, seal etc put in it?

Ken in Toronto 416 570-4957 cell

I tried the rebuild route... too expensive. Stick around, mine might be available soon.

[Q45tech]

Checked with Byron he says impossible to make fit.