Ed Petry

Hello everyone,

Hope the weather is not too harsh in your part of the world.

I am starting to plan for tranny repair in my MY81 5-speed. I've researched using PET and online yet do not have a good feeling I understand the topic enough to make a decision. I am hoping to ask for advice from those that know about these things (and vastly more than I do).


Currently I am surviving with an 28.08 model in need of synchro's. Bought out of a Junker to get the vehicle moving. Not the best situation yet the vehicle is moving and just a grin to drive.
As I said, I am looking towards fixing the tranny and wondering what the options are and the best path forward may be.

Back story:
The tranny in the car was not the original when I bought it. As best I can tell is it was the 2nd, 3rd or 4th one. No issue with that.

I have the following tyranny's / parts:
05 - busted -- 5th gear snapped off at the bearing (shaft was missing the splines, too). Otherwise, internals may be good, maybe not. Tranny installed when I bought the vehicle.
05 - in pieces -- bought as spares. PO stated various parts are in good shape, others not so good. I think 5th gear is good but 1st is not. Forget what they said about the other gears.
08 - needs synchro's -- 1st synchro bad, 2nd synchro poor, 3rd, 4th & 5th synchro's are good. Junker tranny. Bought and installed to get vehicle moving (along with the TT).

MY81 5-speed.

Questions are:
--Are parts inter-changeable between the 03 & 05?
--What are the major differences?
--One more reliable than the other?
--Is one a better tranny?
--Is one model preferred over the other?

Does the community think I have the hard parts to create one good tranny out of the three?

Bigfoot928

...

Ed Petry

Thanks 928sg.

Sean & Greg - and thoughts?

Petza914

LOL

soontobered84

That was just mean wasn't it? Kinda like cow-tipping or something.

Zookie

i would defiantly check do a through PPI first but if that floats your boat, go for it

Bigfoot928

...

dr bob

I've seen SeanR and his wife at the same time, so can discount a certain amount whatever tranny expertise you think he has, at least in this particular context. It's not something that comes and goes, is it?


Meanwhile... PET is always an interesting read when comparing gearbox stuff among years. Porsche is reasonably good about using the same part numbers on identical components, so not much chance of PET calling out different numbers when in fact the parts are the same. Also, the WSM offers the gear ratio numbers for the transmissions in question. If those are different, the gearset parts will be too.

NoVector

GregBBRD

Not much is the same, in terms of gears, between the 05 and the 08 transmissions. The ring and pinion ratio is different, 5th gear ratio is different, which makes all the other gears also different.
Synchros, hubs, sliders, and most of the "soft" parts will interchange, but the odds of finding good synchros and sliders, in any of those 3 gearboxes, are slim and none...unless you want it to last, without grinding, for just a few miles.
I'd suggest taking the two 08's apart and see what is good and what is bad. Just keep in mind that the sliders wear almost as fast as the synchros and it is a very rare gearbox, these days, that doesn't need both. (I've got 5 "early" (pre '85) gearboxes apart, right now, and there's not a slider good enough to re-install in a single one.)

Ed Petry

Hi Greg,

Thanks for the advice. Appreciate it.

I assume from your advice the 08 transmission is a better solution than the 05. Is that correct?

Thanks again.

GregBBRD

No...almost the same exact stuff, different gear ratios.
It just appears that you have more 08 "hard part" pieces ro work with, than any other type.