traction control & limited slip differential

[qship96]

Well,today I did a little test! found a ice patch near the curbside of the road going uphill in the neighborhood-stopped car with one side on the ice,the other on dry pavement-turned off the traction control and tried to accelerate up the hill-zero progress! car wouldnt move an inch-tire on ice just spun-telling me the limited slip diff. is completely shot at 151,500 miles despite ANNUAL gear oil changes using fully synthetic premium fluid.then switched the traction control back on,car made it up the hill on this ice patch easily! so for all those who think traction control is not beneficial{usually those who dont have it,by the way} you are wrong-it is the only way i could have moved the car over this patch of ice.

[Q45tech]

Why things have a 70k warranty not 150k.........the viscous assembly is sealed all that affects it is overheats or just plain mileage. The diff fluid is for the gears and bearings.

Why I changed my diff at 200k with one from a 50k wreck.

[PoorManQ45]

I agree that TCS is great Sometimes. Like in your situation where you couldn't moderate the gas pedal lightly enough to get going on the ice, the TCS did the job. But there are times when TCS is bad. Sometimes the TCS will not let either of the wheels spin if it gets no traction whatsoever, but if you turn the TCS off, you can get the wheels to at least spin, which gives you a greater chance of moving.

[Jesda]

Nifty:

http://www.q45.org/intrepidtraction.mpeg

[rover3l]

Tire compound at weight over the rear axle make the biggest difference. My Q45a has a working LSD and TCS but can still be a problem in snow and ice. Fitting Pirelli Winter Sports and having 8 bags of kitty litter in the trunk transform it.

[Jeff Williams]

I hung the frame, on the Q45t, and only one rear tire spun. I had to rock the car, off the frame.

I was pissed, that teh LSD didn't work, but not nearly as pissed as Iwas, about th ebuilder, that poured the driveway! They had such a bad angle, nothing but a HUMMER would have made it down the driveway.

[squeefoo]

A viscous coupler from Joe is $900 OUCH

Probably not too bad to put in but, OUCH

[Q45tech]

The early Q had $20,000 in factory cost parts in 1990 dollars that would be $60,000 today at dealer retail and another $40,000 to replace them all.

But you can't get a new engine or transmission so maybe only $85,000...........most people never even spend $30,000 over 15 years even if wear and tear items [shocks, belts, tires & brakes are included].

The complete differential is ~~$3,000 plus change labor.

Years ago buying those blown chain guide low mileage cars for $1000-$1500 was a parts bargain. Now all the Q are pretty tired [worn parts] unless you get lucky.

[squeefoo]

$3000 ? Makes me wonder if somebody rebuilds viscous couplers or if they can be. Maybe a 300ZX VC will do.

I just did a huge double burner last summer I felt like a kid again

[Q45tech]

The sealed viscous is only $900 but you must disassemble the diff and reassemble the diff correctly to change it.

All in all they have a better lower cost operational life than the clutch type units...........just the 1-2 revolution lag time till the fluid warms up from initial slipping.

Easier to buy up wrecked Q diff units for $300-$500.

Every old Q owner should have a few wrecks in the back/front yard.

[PoorManQ45]

Every old Q owner should have a few wrecks in the back/front yard.

Dennis: Are you by any chance from the south . We've lost some cars in the backyard at my house

[Q45tech]

Some people buy whole steers at one time for multiple freezers, just easier to buy sets of mostly working parts on the hoof so to speak.Better if you live in the country/on a farm where neighbors don't get upset.

A revival of the past ........when some of our immigrants have a dozen vehicles [in various states/conditions] in the side yard...........sure beats chickens [especially roosters] and pigs.

Ever seen your neighbors kill a goat/chicken in the backyard.

What's a few Q to complain about.........same with LS, BMW,MB.......gotta have those cheap parts when you need them.

Actually all my parts are neatly arranged in the home garage storeroom on 6 - 6' 4 level racks.Our county has ordinances against parking cars on grass, dirt, or stone.

[redmanfx]

I've started my own collection of spare parts as well. I've got a spare for most of my active parts(accumulators and such) and have recently added some knock sensors. Call it small but it will be growing. I'm still in the process of replacing the working parts and the older the car gets the harder to find decent wrecked car parts.

Can't go wrong with the prices though. Makes it well worth the hunting!

red

[louiegz]

So what are the long term repercussions if you don't fix the LSD? Will it cause other damage to other parts of your differential or car? Or could you just let it go and your car will still drive normally? I always thought that LSD is a little redundant with the Qs that have TCS. Better to have both but I could live without the LSD.

[mpaton_2000]

The sealed viscous is only $900 but you must disassemble the diff and reassemble the diff correctly to change it.

All in all they have a better lower cost operational life than the clutch type units...........just the 1-2 revolution lag time till the fluid warms up from initial slipping.

Easier to buy up wrecked Q diff units for $300-$500.

Every old Q owner should have a few wrecks in the back/front yard.

Sorry to take so long to reply to this. The Q45 LSD appears to have a very softsetting. I bought my first Q used from the dealer in May 2000 with jus under 50K miles. Just before 70K miles and the end of the warranty, I was going over everything to check it would have a good chance of making the 250K that Q45 was predicting to be possible if you looked after it.

I noticed that with the trunk empty and gas tank low, if I stopped with one wheel on wet grass and one on asphalt, and accelerated hard, then I could easily show 60mph on the speedo while the scenery moved by at about 15 mph. I could have made the speedo show more, but I've learned that this trick can break diffs.

So I documented what I'd done, and complained bitterly to the dealer, and slightly to my surprise, they replaced it with a new rear end, under warranty. So I put 1000 miles on it, and repeated my test, just before I took it back to have Mobil 1 put in it, and the test results were exactly the same!

So I conclude that the VC in the diff is not intended to be especially noticeable. So I wouldn't worry about the performance of your diff. I don't believe a new one would help.

Michael Paton