I bought a parts car S4 hoping to use the transmission because this one has LSD and mine does not however it will not go into gear. No matter what gear its in it just rolls like its i neutral. We noticed this when we were trying to remove the half shafts and putting huge amounts of torque on the axle nut that the car would use roll. I tried manually selecting the gear from underneath but it didn't matter just rolled. I have never torn down a automatic gear box so I have a feeling this could be expensive. Any ideas? My trans in my car is perfect could I just swap diffs?

Thanks

 

There is a good chance the LSD is still good. The automatic will slip in all gears. There is nothing like a standard that locks the engine to the gears. The torque converter takes care of this. However, when the transmission is in Park there is a big gear and cog inside the transmission that locks the wheels up. You should be able to find park - it is all the way back on the trans shifter. That should lock the transmission for you.

If this does not do it then I would get very suspicious of the LSD. It has clutches in it. I am just guessing here but if the clutches in the LSD were completely shot then maybe the axles would turn when the transmission is in Park. I have never seen this but I guess it is possible.

Swapping out the LSD is not a big job. I have heard it can be done with the transmission in the car but you have to remove the gas tank. You will have to shim the new differential carrier and change to your ring gear. Bill Ball discovered that all LSD are not the same. You should swap or check the rear cover on the differential so the speedometer will still get a signal.

I will assume that you have a 87-88 parts car. If you have an 89 however, then you can gain something by using the lower geared ring and pinion which can be swapped into your transmission.

Rebuilding an automatic transmission is not too bad a job, but I think it requires some experience to get it right. Unless you have done some I would leave it to professionals. Good luck

 

The car rolls really easy. We had all the wheels on the ground and the car just rolls like its in neutral. The car was dragged back to his house a few blocks I found so maybe the trans is toast..? The car was in a fire and was stuck in park. No one thought to lift the back of the car and just manually select is in neutral instead they just dragged it. crazy.. I did drain the fluid and everything was clean with no metal shavings.

 

for lack of a better description the park detent is a mechanical pawl that catches on a gear. drag it around with a big tow truckj and you break the lever arm. Happens all the time because junk is junk they use fork lifts to move stuff around the salvage yards and park by Braille if you do not hit the car next to you you are not close enough !!

 

Park detent? Cool thanks never heard of that before. Any have a part# for that PET isn't showing anything and I was curious the price.

When I manually move the gear selector arm on the transmission it almost feels like nothing is connected to it because it just moves way to easy between gears. Would this be the "park detent"?

 

Check out this thread.
https://rennlist.com/forums/928-foru...ut-1-foot.html

 

Park pawl is broken.
R N D 3 2 all work as neutral when engine off and converter not spinning.

 

What's the difference between the park paw and park detent? Is the park paw fairly easy to replace? Thanks everyone

 

you will find out the damage after you remove the differential ,
you will also need to drop the rear subframe so the diff housing will clear,
no need to remove the gas tank,
the pinion will also need to be swapped so it stays with its matching gear

 

I'll get it removed next weekend. I had to replace the torque tube in my pink one so i'm all aware how "fun" of a job this is..

 

Late to the discussion-- I want to be sure I am reading the OP's concerns correctly.

Consider that the autobox locks the pinion in the "park" position. That keeps the two axles from moving in the same direction at the same time. With the trans on the floor, you can turn one drive flange, and the other will turn in the opposite direction freeley even with the parking pawl engaged in "park" position. A limited-slip diff will provide some resistance, but won't lock the two axles together. Per GB, we expect about 25 lbs/ft of breakaway torque on a new set of clutches and disks. That goes downhill as the car is driven. to the point where most cars seem to not have much 'limited' in their LSD's by 100k. I know mine is a little wimpy at 100k, less than 15lbs/ft breakaway torque required.

 

Hi Bob,

With the car in the air if I move one of the rear wheels one direction the other wheel follows that same direction. At first when I first got the car one wheel would turn the opposite direction though so I don't know what's going on. Than again the car will not go into any gear PRD12 as its always in neutral. There is no question the car rolls beautifully. lol

 

OK--

With the car up, can you verify that moving the selector lever inside the car actually moves the arm on the side of the gearbox? My car tried to strand me right close to the house when the shift cable broke. No connection between the shifter and the trans. I rolled the car onto a curb to get enough room underneath to reach in and move the arm on the side of the trans. Fuel pump jumper does alternate duty so the car could start in gear. /// Straying from your issue, just saying that it's possible.

 

OK, so it appears you have an LSD from the wheels turning in the same direction.

If the car will not move from neutral, check that the gear selector on the trans is actually moving with the lever. There is an adjustment nut - it might have come loose [Oh, dr. Bob already got that.].

Check the fluid level. With the engine off, the reservoir should be overfilled. If it is not, fill it to the top. Keep adding fluid until the level stays right at the top and no longer falls over a minute or so. With the engine running, the fluid level should drop, initially to just above the cold minimum line (lowest line on the reservoir). If the fluid level does not drop, the primary pump is broken, and that is why the car does not shift gears. If the fluid level drops below that, stop the engine. Add fluid until full again, start the engine again, repeat until the level stays just above the cold minimum line.

 

This trans is from my parts car (engine fire) so no way to run it. When I drained the fluid from the trans it was definitely clean and full of fluid. I also drained the diff fluid and it was also clean. However there is something definitely not connected inside the transmission for when you select the gears and the lever on the side of the transmission turns way to easy for a gear selection. I'll no more when I get her out.