rdisney

Mark,

I definitely want to go this route. Please let me know if you still have a used Input Shaft Bearing 78-84 and the cost.

All,

This morning we removed the pinion shaft assy and when I spin the input shaft by hand, it is not real smooth but no real rough, and makes a light rumbling sound. Would this light roughness be normal?

Thanks,
Ron.

ROG100

If you get stuck and have to buy new my price is $608 - every little bit helps.

danglerb

Yipes, I didn't like the price when they were only $500.

My vote goes for some kind of fixture since pretty much all of the old tranny's will need the input bearing replaced by now.

What level of "quality" of machining needs to be done? Router template?

Mike Simard

It's just like cylinder heads where it can be done well or done poorly and both would be called "machined".
You want the bore to be accuratley sized, round, true to the shaft datum and a good finish. It would be difficult to duplicate the Porsche bore quality for a larger size. Surface finish is usually what get missed because it's an interference fit but a true surface is important to keep the bearing from moving, splitting the case or wearing stuff out.
Any competent machinist should be able to do this but there's alot of room for incompetence to sneek in and alot of ways to go about it with minimal effort.

GregBBRD

Replace "machinist" with "mechanic" and that pretty much is what has happened to almost every 928 that comes into my shop.

rdisney

After spinning the input shaft by hand again, I believe the bearing is ok. The roughness I feel reminds me of a tight wheel bearing while doing a repacking job. What I don't know is if the input shaft bearing should be that tight.

Ron.

john gill

If you have gone to the trouble of removing the transmission , and have suspect parts replace them or at least get a second opinion . The cost in time and effort to repeat the exercise again is enormous .
My work practise anyway .

Porker928

Hey Guys

I recently bought and fitted a 1990 GT manual transmission to my '84 Euro.

I got it from a scrapyard and it had done a reported 90,000+ miles.

Its working great but at low rpm / high torque situations - like pulling away from junctions - its making a ratterly bearing type sound.

(Its not coming from the diff. because I fitted a new one.) So I'm presuming its the input shaft bearing - are these the symptoms ??

Ben

john gill

Hello Ben

You said the transmission was from the 90 GT , this is a psd transmission , with the multi plated differential pack . I know you siad you fitted a new one , but what did you fit ?

What did you do with the diff yoke in this unit , it is supposed to be pinned from the slave cylinder , diff back top , and located with the lower back distance setting bolt ,if this is not done could be the cause of the rattle .

Porker928

I don't believe all the Euro GT's had PSD? - especially the first ones.

The box is a G28.55 with LSD and a new 4 plate LSD has been fitted.

Ben