Rear tires "skip" when turning hard

[AWDGreenMachine]

Hi, I'm new to the forum and this is my first post. Unfortunately, it's about a problem with my 95 AWD Talon. When I Make a U turn or a tight turn( like in a parking lot), the rear tires hop or skip. Atleast thats what it sounds like. Any ideas on what it could be? Thanks in advance!

 

[GORBS88]

It is the center diff in the tranny .....Either someone has welded it before you bought it or it has piled up .....Now your front and rear wheels are locked together 50/50...Was the car modded when you got it or stock??? if it was stock then you need to pull your tranny...or drive it till it breaks....mine was hooped when i got mine and the spider gear was stuck to the washer so it was alright to drive....that might not be the case with yours....

 

[AWDGreenMachine]

It was stock when I bought it and as far as I know, was never modded. Hmmm, good thing my car came with a warranty. Thanks!

 

[Awdboost]

Sound like a broken center diff. If you can spin any of your tires then you have a problem.. lot's of people bust there center diffs. It happen to me..

 

[AWDGreenMachine]

Well, I took the car into the place I bought it from yesterday and the mechanic said that he took a look at the center diff and it was fine...no leaks, fluid looks and smells good. I don't really believe that he checked, but I did let him know that I would be taking the car to an Eagle dealer. He agreed that is the best thing to do and to let him know what the problem is and they will fix it.

Took the car in to the Eagle dealer today, explained the problem to the service tech and he said that it is most definately the diff and told me to bring it in first thing in the morning to take a look at it, test drive it to be sure. I was also told by the service tech that the cost for that type of repair is around $2000. Does that sound right? Another thing that's weird is that as soon as I left the dealers lot, I got a CEL! It's like the car got mad 'cause I want to get it fixed. I have about 2 months before my warranty runs out so I need to get this puppy in tip top shape.

One more thing I want to add is that when I push the clutch in, It doesn't want to coast forward or backwards. Does that still sound like the center diff? Hopefully I find out something tommorow.

 

[jtmcinder]

Weekend project:

Get three friends (needed for second test).

Put that car on jackstands.

Test 1: try to turn the rear wheels in opposite directions; this should be possible; it might be difficult (if you have a rear VC), but it should be possible, especially if you turn slowly.

Test 2: have two people hold the right-side wheels from turning; try to turn the left front and left rear in opposite directions; this also should be difficult but possible.

If the car fails the first test, your rear diff is seized. If the car fails the second test, your center diff is seized.

If it's your rear diff, consider replacing it with a Kaaz 1.5-way if you can't get a junker.

If it's your center diff, consider getting a Quaife or Cusco.

- Jtoby

 

[unior]

oops

 

[Twisted2g]

rear lsd is starting to lock up

 

[4pistons]

This may help explain things a little better. http://www.dsmtuners.com/forums/showthread.php?t=173481

the mechanic said that he took a look at the center diff and it was fine.

Since the center diff is inside the transmission you can't visually inspect it without disassembly. He meant the transfer case, which is bolted between the transmission and the driveshaft. If he really did think it was the center diff then don't ever go there again.

I was also told by the service tech that the cost for that type of repair is around $2000

A complete trans repair including the center diff could run $2000 but DON'T TAKE IT TO A DEALER! Go to BM tranny or Sheppard or TRE. They know what they are doing, they'll do it for less and beef it up too. Read your your warrantee very closely, I highly doubt it's covered. I've never heard of anyone getting it covered.

Rick - '91 GSX

 

[beat90tsi]

What is the difference between the center diff and the t-case?

 

[pianoman]

Have you checked to see if you car even has a lsd? It may not. When I got my current talon it did the same thing and I though it was all fubar'ed. I didn't even bother to check since I figured that they all came with lsd's, and I just figured it was being a dsm. I actully was talking with Steve once, and he is the orginal owner of his eclipse. He says that the lsd was an option on the talon but was standard on the eclipse's. But my tires skip because I don't have a lsd I have open diffs front and rear. My buddys blazer does the same thing when its in 4wd mode since he has open diffs, and my uncles jeep is the same way also.

Oh yeah, to check if you have a lsd, right above the vin sticker on the drivers side door, there will be an orange sticker if you do. If there is no orange sticker, then you have an open diff in the rear.

 

[4pistons]

my tires skip because I don't have a lsd I have open diffs front and rear

Not true. If all the diffs were open then all the tires would turn independant of each other and there'd be no "skipping". If your rear tires are skipping then either your rear diff is LSD and/or your center diff is locked.

What is the difference between the center diff and the t-case?

You need to brush up on AWD basics. A differential is a device that allows two connected axles to spin at different speeds in order to negotiate turns smoothly. It "differentiates" the speeds of the axles. An AWD DSM has three of them. One for the front axles, one for the rear axles, and one for the front and rear output shafts in the tranny.

A DSM t-case is a set of gears that transmits power from the transverse direction of the engine/tranny to the longitudinal direction of the driveshaft to send power to the rear. The gears are always meshed, it doesn't do any "differentiating."

Rick - '91 GSX

 

[pianoman]

My gsx which had the lsd never skipped and those were locked correct? Since its a limited slip? Also Why would my uncles jeep and my buddys blazer do the same thing when they are in 4wd mode? The awd is binding on itsself.

 

[zephyr_8]

Your buddy's blazer and the jeep both have different 4 wheel drive systems than your dsm. All wheel drive cars have three differentials and they are always driving all four wheels(well not always, but for simplicities sake they do). The four wheel drive systems in the blazer and jeep use only two differentials, one in the front, one in the rear. The power is sent to the front wheels usually through a chain driven front driveshaft. The 4wds shudder like that because the driveline is binding up because there is no center diff to take in differences in speed of the tires.
Your open diffs don't make your car skip, they are designed to allow both tires to turn at different speeds. Because they allow the wheels to turn at different speeds nothing binds up when the car turns. Lockers(or screwed up open diffs that are now locked) on the other hand don't allow differences in the speed of the tires so it chatters, binds and jumps. That jumping is caused by the driveshaft twisting up to a point and then rebounding. Limited slips allow a little bit of speed differential between the tires and "lock" when wanted to(depending on design).
Hope that makes sense and clears up a few things.

 

[beat90tsi]

A DSM t-case is a set of gears that transmits power from the transverse direction of the engine/tranny to the longitudinal direction of the driveshaft to send power to the rear. The gears are always meshed, it doesn't do any "differentiating."
Rick - '91 GSX

Rick,
Thanks for the explanation, I always hear both phrases thrown around and I never had a good understanding of the difference. Due to my experience with Jeeps, the T-case was the only unit necessary, and in many cases acted as both. So the viscous is inside the tranny, and the t-case doesn nothing but transfer power the rear wheels. It all makes sense now. In Jeeps, the t-case puts power to both axles, and in many models has the ability to remove power from the front wheels as well as shifting the vehicle into low range.

Are longitudinal AWDs, like 6/8cyl audis, and subarus more similar to the SUV design?

 

[jtmcinder]

Are longitudinal AWDs, like 6/8cyl audis, and subarus more similar to the SUV design?

No. Subarus are similar to DSMs, having a center diff. The larger Audis are completely different. One end of the car is connect to the transmission through gears. The other end gets its power through a VC; not a differential with a VC on it; the power actually goes through the VC. I think I covered this is a tech article. The A4 and S4 Audis are like DSMs.

- Jtoby

 

[AWDGreenMachine]

Taking the car in to get fixed Tuesday. Dealer said it was the viscous coupling or something like that. I just wanted to update you guys.

Thanks

 

[Limegrntaln]

It still sounds like the center diff gears to me, unless it was welded, (and I have never seen a stock clutch strong enough to break a center diff) but you would know if you were trying to back up while turning out of a parking spot, feels like it gets progressively tighter.

If its broken, I would send it somewhere to get it welded or get new gears, if they take the entire tranny out to do the center diff then they are doing too much work, you can get to it from the right wheel well.

$150 welded, you need to get it welded by someone that uses a jig because it turns in the tranny and if welded off center could wear out the outer bearings. Ive heard of DSM shops welding them in the car, but I like how Jon @TRE did mine.

You can also get a 4 spyder one done for like $450 with a servicable core, or you can go to a quaiffe or Kaaz for $800-$1200

 

[4pistons]

Dealer said it was the viscous coupling or something like that

It's not. It's your center differential. But you'll learn that soon enough when they change the VC and it still does the same thing. When a VC goes bad it usually loses its ability to lock up and "freewheels."

At least four guys on this thread pointed you to the center diff and we all offered ways to check it. I also offered some learned advice - "DON'T TAKE IT TO A DEALER!", and where did you take it?

But you're saying, "The dealer knows it better than anyone." WRONG! Through the past ten or twelve years us DSMers have taught the dealers WAY more than they have ever taught us. They replace components according to a book, they don't generally diagnose or analyze problems. And especially on a specialized vehicle like an AWD DSM.

Going back to 1990, the first of the AWD's, they've had to learn the mechanics of EVERY vehicle Mitsu, or Eagle, or Dodge made. The Talons, Eclipses, and Lasers were only a small part of the cars they worked on, and the AWDs were only a tiny fraction of that. So, although it seems "secure" to take it to a dealer, you're so much better off taking it to a DSM specialty shop that has been working on these specific cars and their problems for many years.

Just my $.02, plus about a buck and a half!

Rick - '91 GSX

 

[4pistons]

get it welded by someone that uses a jig because it turns in the tranny and if welded off center could wear out the outer bearings

I welded mine on the bench five years ago with no problems. The way I do it ( http://www.dsmtuners.com/forums/showthread.php?t=173481 ) all the welding goes on INSIDE the center diff case and all the gears fit in precise places. After the welding is finished nothing inside the case spins. So I don't see how that effects the bearings on the outside of the case.

Rick - '91 GSX

 

[Limegrntaln]

I got the info from Jon at TRE. Im talking about the bearings immediately outside the center diff on the top and bottom of the diff, I.E Splined shaft. In your How TO thread im talking about part number 6 if you already have broken gears then you have nothing flat to sit that piece on when you weld, there fore getting #6 welded as straight as possible, think about it if that #6 shaft was a little cockeyed as the diff spun, at speed that shaft would speed wobble all over the place, like a piece of bent pipe spinning on a laithe. I see what you are saying though with welding 4 to 6 maybe john welded 6 to the 4 way and put 4 over the shaft after he welded. Dont know, thats what I got out of it anyway.

Maybe it was bad info, it was like 5 years ago, Im getting old and sometimes my mind wanders.

On a side note the only time I would take it to the dealership is if you have a connection there. I mean when I took mine to the dealer, the only guy that worked on mine was Matt who owned a 12 sec 3Kgt and an 11 second 1G AWD..ooh and 2 starions with a bunch a mods on them, and thats the only guy that I let work in my car from the dealer. I knew Matt Knew his shi@. These days though those people are getting harder and harder to come by.

 

[AWDGreenMachine]

I haven't taken the car in yet...not until Wednesday. I trust what you guys are telling me so, I'll just tell'em to repair/replace the center diff.. Just incase there was some cofusion here, I just took it to the eagle dealer for a diagnosis not to fix it...another shop is gonna do that.

Thanks for the help! Like I said before, I'll keep you guys updated. Oh, just 1 question before I go...about how long should it take for them to replace the diff.?

 

[Limegrntaln]

Heh since im in Korea for the past 10 months, I havent been under one in forever, but I thing there are 4 or 5 bolts and it comes right off then you can pull it away from the driveline, after taking off the little half moon flywheel shield, I would say no more than an hour out and in and filling it with fluids.

 

[4pistons]

I thing there are 4 or 5 bolts and it comes right off then you can pull it away from the driveline,

That's the TRANSFER CASE not the CENTER DIFFERENTIAL! Don't you guys have a shop manual? The center diff is INSIDE the transmission. The tranny must be disassembled to get to it.

Please don't take it to a dealer....

Rick - '91 GSX

 

[JPGRL]

I took my car to a dealer for the t-case recall, and it locked up again 2 miles from the dealership (on the way home). At that point they blamed my *newly rebuilt* tranny. We suspected the center diff, if anything, and I briefly looked into having Aamco diagnose the issue. Their quote for diagnosis alone was pretty low, like $400 maybe? It'd be way cheaper at a place like that then at the dealership. In the end we took it apart ourselves and saved even more, but if you don't know the transfer case from the center diff, taking your tranny apart yourself isn't recommended.

(and the problem ended up NOT being the tranny after all. So much for dealerships being the *best* at diagnosing and fixing your car.)