wa_nin

I recently purchased a 1979 5 speed. The car displayed clutch issues on the drive home. I contacted the PO and he brought tools to look at the car with. We identified the problem, but he also commented that the transmission likely will go out soon, and he gave me another transmission.

I'm looking for someone in the Pacific Northwest area with tools and experience who would be able help me swap the transmission. Ideally I would save money over mechanic costs and learn more about my car and you would get paid and get the chance to teach a newbie.

Thanks

danglerb

Not much point in putting in a used transmission without rebuilding it first.

On the bottom roughly between the axles there is a flat spot with trans ID stamped into it, all of the ID would be useful to know from both transmissions.

James Bailey

How does one know that a 5 speed trans .." likely will go out soon.." ??? And as pointed out the vast majority of early transaxles need to be overhauled if you want it to shift well into 2 nd gear. So drive it until the transmission does go out....but I am not sure what that means. Then work out the best option to fix it.

wa_nin

danglerb: I don't have any way of getting to the ID on the one under the car, I don't have jacks and stands. The number on the transmission the PO gave me is G28/03/12 119 0209. Could you elaborate on why it is not worth it without rebuilding?

James Bailey: It's shifting rough, has a lot of miles on it, and the PO said the owner before him raced and did a lot of power shifting. Can you elaborate on the 2nd gear issues?


Thanks both of you for your replies

karl ruiter

The early tranny is prone to notchy/noisy shifting, but not catastrophic failure. Even units with fairly low miles after a rebuild have been reported to shift somewhat poorly. The standard approaches are to 1) live with the shifting as is, or 2) upgrade to a later model transmission and torque tube. Shifting can often be improved with careful attention to the clutch mechanism. Three primary stories there:
1) Air can be really hard to get out unless you use the 'burping' procedure you can find here
2) The center plate must be properly adjusted
3) The clutch plates can hang up on a worn spline shaft.
The good thing about these is that none of them cost much money to address.

wa_nin

Thanks for your reply karl ruiter.

Do you know why earlier rebuilt models are often reported to shift poorly?

Is there a way to double check the year of the extra transmission I have with that ID?

Thanks for the info about the clutch adjustments.

Vilhuer

G28/03/12 119 0209 is '79 MY gearbox with LSD.

Roy928tt

Early 5 spd boxes have a pathetic Porsche designed syncro ring, which struggles to perform its duty, even when new. Later boxes used a Borg Warner style ring that performs correctly. Early boxes are renowned for being poor shifters and this manifests itself in a very poor change into 2nd gear, mine improved simply by changing the oil, I also swapped syncro rings around ie 5th onto 2nd etc, That was a very poor idea on my part......

Cheers Roy

danglerb

Power shifting I have real doubts on being possible even with a fresh rebuild on the early transmission, as least power shifting as I do it in my mustang. Accelerator to the floor, drop the clutch as the tach is passing about 2500 rpm, then about 5500 rpm shift into second without lifting the accelerator, same for third etc.

The "new" used tranny could be no better or worse than the one you already have. Rebuilding isn't that hard, and generally speaking the earlier you are in the wear cycle the cheaper it is to rebuild. Once syncros wear enough to start making grinding shifts, its the dog teeth that are being worn, and shedding metal into the oil.

Age and miles are not the major factors related to wear. How the car is driven, how well the clutch was adjusted have more to do with condition, so with the early transmission its best to assume it needs a rebuild.

wa_nin

Vilhuer: Thanks for looking that up. I'm assuming LSD is limmited slip differential, what's MY?

Roy928tt: That clears things up, I guess I thought everyone meant it would be worse by changing the transmission, as opposed to a problem persisting. Is the transmission fluid simple to change? Did switching the rings help the lower gear shifts but mess up the higher ones?

danglerb: So does a transmission rebuild basically consist of replacing the syncro rings?


Thanks everyone for your replies.

Landseer

They don't need to be perfect to be usable.

The early ones are what they are.

We just put a Euro 80 box into an 84 that kept popping out of 4th.

The Euro box requires a careful 1 to 2 shift, especially cold, but its a vast improvement and the car is enjoyable again.

Anybody powershifting one of these cars... shouldn't be.

atb

A few of us locals have shop with a lift and tools. We could have the tranny swap banged out in no time, but probably wouldn't be able to get to it for a few weeks.

Vilhuer

See post #27:

https://rennlist.com/forums/928-foru...questions.html

danglerb

MY = Model Year.

Depends, "maybe" just syncros, but you don't know for sure until its apart and inspected. Most early transmissions may not "need" a new input bearing, but they get constant wear over time, so if long term ownership is planned they should be replaced. Its not unusual for the parts to exceed $1k, even with no major issues.

A lot of 928 repair costs depend on how tolerant you are of things being not right, noisy, or ok for now and fix it "later".

wa_nin

Thanks for the reply Landseer

atb, PM sent

Vilhuer and dangerlb, that seems obvious now, thanks for pointing it out, hah.

danglerb, good to know, thanks