jkmcafee

'85 GS 13A has 4 speed automatic (3 spd + OD). Only has 78k miles and engine now runs great. The automatic transmission seems to have an issue but I'd like advice as to the best way to determine the actual problem.

Symptom: When accelerating from start or low speed or turning at low speed, there is a "slipping" sound that seems to be either transmission, differential, or wheel bearing related. I initially thought it may be LSD related but the GS does not have LSD. I did, however, change the differential fluid just because that was an easy thing to try. Did not help.

I really think it may be the transmission. accelerating at low speeds when going straight causes a slipping sound. I think I'll try changing the transmission filter and fluid next but wanted to post for advice from this forum.

Thanks in advance for your help

P.S. - my thought is this may be the perfect excuse to change over to a manual transmission!! I have an '85 GSL-SE and it is amazing the difference in performance between an Auto and 5-speed!

KansasCityREPU

iTrader: (9)

I've done the auto to manual swap to my 1985 if you need any pointers. I also have a very low mile auto trans if you need one.

jkmcafee

Anyone had similar issues?

Frogman

Is the fluid ok? when you say slipping, do you mean a grinding noise or a wooshing noise, it could be the carrier bearing at the end of the trans. I have literally run my trans almost dry and the only thing that happens is it slips out of gear. you hearing sounds might mean something is seriously wrong with it

jkmcafee

It seems to be more of a grinding sound with a little "jerk" to it. Back in GA for the holidays, drove it today and noticed that it is worse now that the weather has cooled off. But it got a little better once it warmed up. Wouldn't this suggest something clutch related? I have not had a chance to drop the pan and change the filter but that's the next step i'm going to take.

jkmcafee

Dropped pan, checked changed filter. The fluid looked OK, but swapped it anyway. Trying some trans fluid additive as a last ditch effort to loosen clutches, but not hopeful.

Have started down the path of locating parts for a swap from Auto to Manual. Here is the list based on my research:
- Manual Tranny
- Shifter, inner boot, outer boot, bezel
- Pedals, master, slave, hard lines
- New clutch, pilot, throw out bearing, clutch fork
- Mounting bracket from surrogate frame

Think I've found a source for everything except outer and inner boots. Suggestions??

jkmcafee

Any lessons learned for this swap that you could share?