What do all these symptoms point to?

[mjc1310]

Okay, got a tough one here. I will spell out every relevant detail I can think of and see if we get anywhere. I have thought about this over and over in my head and can't come up with an answer. I've also searched the forums but no luck.

The car is a '90 LS with 135,000 miles. It is an automatic.

I bought some RS springs this past weekend and threw them on Sunday evening. We went through the process as normal, jacked up the car, got it on jack stands, removed the whole strut tower with spring, replaced it and reassembled. I did not chuck the wheels and was working on a notable incline. I put a jack stand on a piece of the sub frame behind the rear diff while doing the rear springs. I put jack stands directly on the frame when in the front. Also the e-brake was on the whole time.

When we finished, went to back out of the driveway and wasn't able to budge. It was as if the engine completely wasn't engaging with the tranny. After toying for a second, I figured out I could rev up slightly and it would catch and jump forward then completely disengage. The best way I can describe the disengaging was like a clutch that will slip but opposite a normal slipping clutch: when I hold a steady rpm, it disengages, but when the car is under a load such as heavy throttle or climbing a hill, it holds strong. Other notable things would be that when it disengaged and jumps in rpms, the speedometer climbs with the rpm (as if the transmission is still rotating at those rpms?). If I accelerate hard when it engauges, I can cycle through all gears just fine, I just have to be accelerating fast. When placed in park with the engine on, all I get is a harsh grinding sound and I have to pull it out. When placed in park with it off, then turn back on, it doesn't grind, but it also doesn't hold the car in place.

I know FOR SURE that there was no popping or sudden shift or anything while jacking and releasing. I also tensioned all tires once they were on the ground. Fluids are full and correct type. I am not the most familiar with how these drivetrains work.. but should I start with the front diff? Change fluids and pray real hard? Any suggestions?

[James614]

Are all 4 axle stubs fully engaged into the diffs? All 4 roll pins back in the axles to keep them from pushing themselves off the stubs? None of the splines on the axles or stubs sheared? If its not axle related I can't really see how you would have damaged the trans or diffs by doing struts.

[James614]

I think you should start with the front diff, and pray real hard. Probably drain the fluid and see if there's bits of gear that come out.

[Legacy777]

If the car is not being held in park then it sounds like the parking pawl is damaged. How steep was the incline?

You can drain the diff & trans, but I suspect if the problem is the parking pawl, the tranny will need to be disassembled to some extent to fix it. I don't know if that can be done with the trans still in the car or not.

[mjc1310]

Thanks for the feedback!

James614: Yes all of the cv axles were correctly fixed to the male stubs of differentials. Good thought though, that one hadn't crossed my mind. The more I thought about it, it was mainly the issue of putting it in park that led me to the same conclusion that Josh suggested.. it's a gone'r.

I let any sense of pride from self diagnosis down and took it to the shop, where they concluded the same thing.

Sooo, after GREATLY considering doing a 5 speed swap, which I still toy with the idea, I think I am just going to replace it with a used one.

[James614]

Doesn't make sense to me that a damaged parking pawl would cause the issues with driving forward in the way you describe, as I've known vehicles to still be drivable with a broken parking pawl. But nonetheless, whether a front diff or parking gear, it's probably most labor and cost effective to replace the trans anyway.

I highly recommend a 5spd swap, but not something you want to do while you're in a hurry to get the car back on the road.

[mjc1310]

I have gone back and forth on the idea of a swap.. and due to various factors I think I am going to do a straight auto swap for now and look at getting a 5-speed wagon.

Know anyone selling a tranny?