BRM 4.08 rearend swap now available!

[HeavyDuty]

Wellllllll,

I spoke too soon. Yup, I screwed the pooch on this one. I'll post pics tonight. The rear cover on the 90-91 is of a different design, 2 bolt retainers for the rear crossmember as opposed to 4 bolt retention on the 92-96. Also, the grouping on the axle stub holes is different, too. The 90-91 has six evenly spaced holes on a daisy shaped stub. The 92-96 has three groupings of 2 bolts each.

Could you switch the cover & swap stubs? Possibly. Would it be worth it for what I'm doing with this particular diff? No.

Pics tonight, in the meantime, if anyone with a 92-96 Non-TCS car wants a cherry low mileage diff, (80k) it's up for grabs for $300.

[elwesso]

That was great...

After driving the Fred Q, it keeps the 4.08 in the back of my mind..... Id love to have some of that low end torque..

If you dont mind me asking about the cliff notes, what kind of prices are we looking at... id been following this for a while, then I lost track...

[sultan]

Wellllllll,

I spoke too soon. Yup, I screwed the pooch on this one. I'll post pics tonight. The rear cover on the 90-91 is of a different design, 2 bolt retainers for the rear crossmember as opposed to 4 bolt retention on the 92-96. Also, the grouping on the axle stub holes is different, too. The 90-91 has six evenly spaced holes on a daisy shaped stub. The 92-96 has three groupings of 2 bolts each.

Could you switch the cover & swap stubs? Possibly. Would it be worth it for what I'm doing with this particular diff? No.

Pics tonight, in the meantime, if anyone with a 92-96 Non-TCS car wants a cherry low mileage diff, (80k) it's up for grabs for $300.

are you sure that it actually is a 94Q diff? my base model 94 has 2 bolt retainers and 6 evenly spaced holes. the cover is also not finned on my car (like the pic you posted earlier). the J30 has the 3 groupings (for 95/96, previous years had 5 even spaced), but still has the 2 bolt retainer. only car i can think of with 4 bolt retainer is the S13.

i'll take pics and post them if you want (of the diff in my car).

[AZ94Q]

Level Ten, modified torque convertor & 4.08= reinvented Q, down low.

[AZhitman]

So true, so true!

[HeavyDuty]

are you sure that it actually is a 94Q diff? my base model 94 has 2 bolt retainers and 6 evenly spaced holes. the cover is also not finned on my car (like the pic you posted earlier). the J30 has the 3 groupings (for 95/96, previous years had 5 even spaced), but still has the 2 bolt retainer. only car i can think of with 4 bolt retainer is the S13.

i'll take pics and post them if you want (of the diff in my car).

You know what? No, I'm not sure it's a 94 Q diff. I ASSumed since it had 6 bolt stubs & was sold to me from my local, usually reputable yard who claims the "two year only" design 90-91 -vs- 92-96 per his parts interchange that it was a 94.

The two bolt / four bolt retainer made no sense to me, but the axle stub "revision" seemed plausible.

My cover is finned, but the fins are more shallow & shorter in height. I understand there is a difference in the covers from 90-93 & 94-96. (?)

I wonder if they mis-catalogued or mis-identified this carrier? If so, he owes me one low mileage Q diff & a case of carb spray cleaner.

What is the difference between the 90-91 & the 92-96 then?

I'm going to be the Diff-Master before this is over.

[HeavyDuty]

Anyone with a 90(?)-96 Hicas car willing to take a pic of their rear?

Pun intended.

Axle stubs in particular, mounting grouping & also number of bolts for mounting of rear cover to rear crossmember.

[DAEDALUS]

I have a '90 with HICAS. Shoot me an email via my profile to remind me, and I'll be happy to do so later after work. I'm on PST though.

[rsiwicki]

I sent you via email of the pic of the one I bought off ebay. It came from a 1994 Q45t.....hope this helps.

[Jeff Williams]

I just spent 30 minutes installing my rear sway bar, and my 1994 Q, no TCS, has 6 evenly spaced bolt holes, on the axles, and 2 bolts holding the diff to the rear subframe, as well.

This talk is getting me interested in the swap, myself.

I can't have my car doen, for more than a few hours, so I would need to get the new diff, before sending in my core. It sounds like there might be enough diffs out there for this to be the case.

Lets talk cost, and delivery.

Is it in the $800 range, or $1100 range, shipped?

I am thinking about the new torque converter, as well, since mine is slipping a bit, under hard acceleration. I do have 87,000 miles on the rebuild, now. Z1 has a guy that does some mods to the 300ZX transmission. I might try one of those, with a new converter fom PI.

And I just decided to no spend any more money on my car, until I get another one, to drive. Oh well.

[elwesso]

Jeff.. Give it up <trying not to spend money on the Q>. I tried it and it didnt work out so well.. DONT BOTHER, just let it happen

[AZhitman]

Jeff - Pricing will be approximately $800 after shipping.

Find yourself a nice core if you can, that will save some hassle and time.

The shop is pretty much ready to start accepting cores, my guy has enough gearsets to do 10 rearends (and one is MINE!)

Email me when you'r ready and i'll get you the info on shipping.

[AZ94Q]

$800, nice one..

Stillen Kit (not even old anymore) $2.000

70% off..

good job

[90Q45blue]

Greg,

So if I understand this correctly your guy is ready to do the swaps and all he needs now are customers?

That is awesome if I'm right.

What is the estimated turnaround time for this swap?

Nick

[Jeff Williams]

Jeff - Pricing will be approximately $800 after shipping.

Find yourself a nice core if you can, that will save some hassle and time.

The shop is pretty much ready to start accepting cores, my guy has enough gearsets to do 10 rearends (and one is MINE!)

Email me when you'r ready and i'll get you the info on shipping.

Thanks, Greg. I'll start my search, for a core.

Do you think, once he has 2 or 3 cores, and I send him the cash, will he build one for me, and let me send him my core after I swap?

Also, does anyone have an idea, what a stock core is going for?

[HeavyDuty]

Jeff - Pricing will be approximately $800 after shipping.

Hey man, Just a suggestion, but I would also mention that if you were to get one as bad as my original, it could be much more, like $1000-$1200.

Jeff, cores could be anywhere from $150-$300.

Rsiwicki sent me a pic of his traction core:



That looks like the one in my car, but obviously not the one I received from the junkyard.:rolleyes Does anyone have a diff in their car that looks like the one I posted the pics of?

The one exception to rsiwicki's picture compared to my car is the harness on the nose of the unit that houses the Hall Effect sensor for the traction control. I sure hope that can just be plugged & there's no other architectural differences between the years & different models. My salvage yard guy still *swears* the diff I have came from a 94 Q, and that there's a year break 90-91 & 92-96.

I had no reason to doubt it was wrong until I was looking under my car for something else & wanted to figure out if I could remove the diff without dropping the exhaust.

[Jeff Williams]

My 1994 Diff looks exactly like Rob's picture, except I dont have the traction control sensor cable.

[rsiwicki]

If anyone is interested in a cheap 1990 rearend, then contact Patrick (aka Junkyarddog from our NICO forums).... [email protected]

He has a Q45 in a salvage yard in Daytona that just got junked about a month ago due to an accident.

Heavy...maybe this might be the type of rearend you need and it is very close to you (an hour tops from Orlando to Daytona?). I am almost postive it would be less than $100 and it is a U-pull it type of place. Shipping costs me $65 out to California for my rearend.

[rsiwicki]

Hey Guys....I might have my old stock 1995 Q45t with TCS OEM rearend for sale if someone wants to buy it and use it as a core to eliminate downtime during the swap. The pic that Heavy posted is actually of a 1994 Q45t with TCS rearend that I bought off of ebay back in February. I don't really have an idea on price yet, but I paid $125 for the core so I am looking for at least this amount to cover my costs. Otherwise I will keep my original one as a spare. Please let me know if you are interested. I will take the highest bidder if I decide to sell it. Shipping will be probably be another $65 and I can ship it out the same day I put in my new 4.08 gear as I should be receiving the new gear late next week. It would probably be best if someone with TCS was interested in it as I am sure that rearends with TCS are probably the most difficult to locate and that way they don't lose the TCS function as well.

email me at... [email protected]

I will keep all bids confidential and not release them to anyone. I will let you know what the current highest bid is on it if you are interested and again I may decide to not sell it and keep it as a spare....but then again, what am I going to do with a spare??? Maybe I use it as a paper weight to hold down all the newspapers before recycling day????

Rob

Also you will have to contact AzHitman at BRM for the final details on the costs of the swap. This just gets you the core to eliminate any downtime and ti will be shipped to Cali very within the next two weeks if not next week Friday when I get my new rearend.......Geezz!!! talking about selling my rearend!!! I would have never thought such a thing Just joking with all puns intended.

[PalmerWMD]

My stock 91 rear end is also FS.

Fred..

[AZhitman]

$800, nice one..

Stillen Kit (not even old anymore) $2.000

70% off..

good job

THanks AZ - Makes a BIG difference when you don't spend a fortune on advertising...

Now it's just a matter of getting it DONE!!!

[elwesso]

Fred.. wasnt your 91 a 4.08 as well????

(stinks that the 91 wouldnt work on my 94)

[QShip]

Fred.. wasnt your 91 a 4.08 as well????

Welllll Fred, is it true????

[HeavyDuty]

Fred,

If your stock, 91 base, non Traction, non Active, carrier is for sale, I'm interested. I read that it was your original 3.5 (or whatever), not a 4.0

I'd be up for a buy (or trade if you need anything).

Thanks

[AZhitman]

My 1994 Diff looks exactly like Rob's picture, except I dont have the traction control sensor cable.

My 95 diff looks NOTHING like that one.

Well, it has the 6-lug flanges, the 2 big bolt mounts for the subframe, but mine is smooth, like a GM rear cover. What's up with that?

[AZhitman]

By the way, once you get your core, let me know via email and I will reply with shipping info (so I can monitor the # of cores going in and out of the shop and time taken so i don't get overbilled).

[rsiwicki]

well my new 4.08 should me on its way heading east to Miami this very moment and installed on Friday at the dealer. If anyone is still interested in using my old rearend as a core to eliminate downtime let me know as I have not received any responses yet so I might be open to a lesser price.

Anyway...here are some figs that I thought you all might be interested in with using the different gears. The differences between the 90-93 car versus 94-96 car are due to 1st & 2nd gears in the transmission are different. Also this is a theoretical calculated speed that does not take into account tire expansion, wind resistance, etc. but it should give you a very close approximation for 1st & 2nd gear up to about 100mph what this mod does to the cars shift points at redline without JWT TCU (I don't know the JWT TCU redline figure, but I can edit this post easily if somebody gives it to me)

90-93 Stock Car .................................1st..........2nd..........3rd...........4thrpm redline...............6,900......6,900........6,900.......6,900 tire diameter (inches)..26.024..26.024.....26.024.....26.024 Diff Ratio......................3.538....3.538.......3.538.......3.538 transmission Gear.................2.784....1.544.......1.000.......0.694 constant....................336.135..336.135...336.135...336.135

theorectical calc mph...54.23... 97.79.......150.99.....217.56

90-93 With 4.083 Gear

.................................1st..........2nd..........3rd...........4thrpm redline...............6,900......6,900........6,900.......6,900 tire diameter (inches)..26.024..26.024.....26.024.....26.024 Diff Ratio......................4.083....4.083.......4.083.......4.083tranny Gear.................2.784....1.544.......1.000.......0.694 constant....................336.135..336.135...336.135...336.135

theorectical calc mph...47.00....84.74.......130.83.... 188.52

94-96 Stock Car

.................................1st..........2nd..........3rd...........4thrpm redline...............6,900......6,900........6,900.......6,900 tire diameter (inches)..26.024..26.024.....26.024.....26.024 Diff Ratio......................3.538....3.538.......3.538.......3.538 transmission Gear.................2.569....1.479.......1.000.......0.694 constant....................336.135..336.135...336.135...336.135

theorectical calc mph...58.77....102.09.....150.99.... 217.56

94-96 With 4.083 Gear

1st 2nd 3rd 4th.................................1st..........2nd..........3rd...........4thrpm redline...............6,900......6,900........6,900.......6,900 tire diameter (inches)..26.024..26.024.....26.024.....26.024 Diff Ratio......................4.083....4.083.......4.083.......4.083tranny Gear.................2.569....1.479.......1.000.......0.694 constant....................336.135..336.135...336.135...336.135

theorectical calc mph....50.93...88.46.......130.83.....188.52

I will probably see the biggest change, from 1st gear redline mph of 58.77 down to 47.00, as I will be also switching to the 90-93 transmission in another week, but at least for 1 week I will have just the 4.083 in there to try this out alone. This should really change my 0-60 times because I already shift at about 52-53mph (stock) so the one shift is already added in there. This might be different if I already had the JWT TCU with the higher shift point where I might just barely squeeze out 0-60 without shifting. Maybe somebody with a JWT TCU can comment about whether they need to shift before hitting 60mph. I would think that they would need to, but not certain.

for anyone interested in other variables as inputs....check out the link below for how to calculate any of the information as I did above.

http://www.4lo.com/calc/gearratio.htm

[AZ94Q]

calculated mph 54.23 97.79 150.99 217.56

Does that mean a stock first gen 90-93 will go to 54 in 1st gear? I don't remember it being that high, maybe I'm wrong... I don't even think my 94 will do that in 1st, even when manu shifting at 7k.. I thought it was more like 45 or something...

[AZhitman]

Good stuff Rob! That means mine should be on its way as well!

Call me on the core, I may decide to just purchase it for "holding", and pass it on to the next lucky 4.08 owner....

[rsiwicki]

the calculated mph is purely a "theoretical" figure and does not take into account tire expansion, wind resistance, and various other factors as speed increases. Q45tech stated that tires sizes actually increase by 10% at highway miles due to the forces of nature...given that say....8% tire size increase equates to lowering your mph by about 8% (i think) so it would be 58.77/1.08=54.42 which is right at about where my car shifts between 52-54mph.

Greg...I will call you about the core tomorrow. I think that Kevin said yours was done also. I asked him to express ship my rearend out to Miami for arrival on Thursday at the dealer for my appointment on Friday. I think the mechanics will get a nice surpise when they go for a test drive and then when they install my new transmission I hope to be able to hear my tires screetching all the way to my office downtown which is about 30 miles away...then a big smile will be on my face and I will be cheese'n