What to do While the Trans. is Out?

[RWebb]

I know what to do to the engine compartment & the motor itself, but what should I do to the transmission while it is out of the car?

Are there bearings or seals on the various clutch forks, or in the bell housing that should be looked at? (Taking it apart for the strengthening Wevo-istic fixes is way out of the money question right now; so it will be back out in a couple of -- a few years).

This is a '75 Mg cased 915 tranny.

I will be giving it a hand-rubbed patina of Gibbs Brand and organic job-ova' oil (which we import from sustainable farmer's cooperatives of ex-Sandinistas). But what else?

[John Brandt]

replace the gasket that seals the shift fork cover, and take a long look at your 17mm hex head plugs for possible replacement too

[euro911sc]

Clean the bolt holes on the drive flanges... cross threading here sux. Check the seals f/r. Clean the snot out of it. Replace the fluids with consesus recomended Swepco 201 if not already. Check the motor mounts. Powder coat the cross bar signal orange in case you go off track and the gofers need to duck

Best regards,

Michael

[Jim Sims]

Replace fuel lines in tunnel or the rubber portions to and from rear of tunnel if an early car with metal tunnel lines.

Pull off the clutch release bearing guide tube and replace the o-ring that seals it to the bell housing and the input shaft seal contained therein. If the outside of the guide tube (the surface the release bearing runs on) is badly worn or grooved replace it. Don't forget to sparingly apply a small amount of grease on the outer surface of bearing guide tube.

[911st]

Maybe it was just this way on the 72 911's but the only way to replace the rear suspension inner control arm bushings was to do it with the transmission out of the car.

Good luck.

[RWebb]

It just arrived. The ID area (why did Porsche put that on the damn bottom??) is pretty much obliterated. I think I can make out the digits 43777.

To the left are the digits "15." I just looked up transmissions in the PET, and the only 915 type (esp. the ones with mechanical speedometer drives) with a "15" is the 1975 915.40 series, which has a "715" as some sort of designation. Would that 715 be to the left of the serial number? IF so, it appears to be a 1975...



IS there any other place I can find some numbers that will assure me that this is a 1975 tranny?

OR -- is there something else I can look for??

The seller swears it IS a '75. I also asked about the 8:31 ring and pinion. He said it was and that he checked it to make sure it was 8:31. But he also said it had never been apart. How could he check without the ID # or without taking it apart?

The input shaft and clutch fork are rusty.



Jim - I don't see how you can take off the clutch guide tube. (??) I'm used to seeing 2 bolts on type 911 and 901 transmissions, but this one just looks like it is inserted from behind with the thing completely dis-assembled.

[euro911sc]

Randy,

Looks like that one had been sitting for awhile. The pinion should be well lubed up... the guide tube is funny too. Mine had a real problem where it grabbed the throwout bearing and then the bearing would work itself off... thus 'dropping' the clutch. It was replaced and all was one with the world. I would suggest the same with that one. Though I can't see how that would be done...

Best regards,

Michael

[RWebb]

Obviously, I cannot change the pinion, but I will try to get it to work by brushing off the worst rust and then use a rust reducer, followed by more cleaning & some lubrication.

This unit was sold to me by a guy who has several items for sale in the parts section - he assured me by Email and by telephone that the tranny was "excellent" and "perfect." The price was $1,000 + $200 shipping. I just wish he'd been honest about the condition.

Assuming it it REALLY is a '75, I am thinking of doing the following things:

[1] replace the guide tube - if lucky, I can use the one from my 1973.5 transmission that I still have.
I've looked in the PET (v.6 - the program not the pdf files) and it says the Guide Tube different on '73, but same on '74 & gives a p/n of 915-116-087-03 (The '73 vs. '74 difference might be critical since Porsche might possibly have started using '74 parts on the late model (CIS breathing) '73.5 cars).


[2] Maybe replace the drive flanges (where the CV joints hook up). Again, if lucky, I may be able to use the ones from my '73.5 trans.

3 differnt p/n's (types) of drive flanges are shown by PET pgm6 for '75 (+ another type for LSD) - for '73 the p/n starts with 911-xxx
So, that doesn't look good for swapping the things -- but you never know....


[3] Maybe replace the clutch fork with the one on the '73.5 trans.
Some research shows the p/n as 915-116-712-01 -- clutch fork, 1975 - Stoddards's says same fork 1972-86, but Pelican has 2 different p/n's (differ byt last 3 extra digits "M260" & says one w/o M260 works only for 1972-73; --- PET pgm6 says guide tube different on '73, but same on '74

I posted the above in detail in case anybody else ever has the issue - it took several hours of research to see what PET, Pelican & Stoddard's all have to say...

If ANYBODY knows for sure whether any of the above can be swapped from the '73.5 trans tot he '75 one, please post! Each item is $150 to $200, so this could get expensive very quickly.

[RWebb]

I am starting a new thread with a better title that relates to this.....


http://forums.pelicanparts.com/porsche-911-technical-forum/406298-evaluating-purchased-transmission-post3911236.html?posted=1#post3911236