Porsche Enthusiasts Club Forum

Hi all, I replaced my 180K mile gearbox with a secondhand one from Ebay about a year ago. To be honest it's not much better than the one I took off. (Diff bearings and output shaft bearing worn and droning). There aren't many gearboxes about at the moment. Question: would a 1983 2.5 gearbox fit on a 2.5 1986 car ? I am pretty sure the bell housing, output flanges and linkages are all the same but I don't know if the speedo output is in the same place. So will the electronic sensor on my 86 car fit/work ? Thanks for any replies

Have you checked your drive shaft bearings? Could well be the cause of the noise. They can be dissmentled fairly easily and Frazerpart do rebuild kits. If all they need is a new grease then its £14 per end, if the bearing needs changed then its £50 per end.

good point hadn't considered wheel bearings. The noise is a constant drone from the back of the car that gets louder as you go faster (ish). However if I go around a left hand bend putting the weight of the car on the right side, the noise goes away, If I go around a right hand bend the weight is now on the left side of the car and it gets louder. Am I looking a left side rear wheel bearing or dodgy diff ?

Generally its the bearing on the offload side that's making the racket so lefty bends the offside is a howling.
However I have no experience of 944 wheelbearing noise.
A few years ago I had a mysterious noise that varied with road surface. I checked the prop,the bearings and just about everything and still that damned noise. I had some rally remould tyres fitted, these had a series of blister like cut treads which were compressing air and creating thousands of fart like noises as you drove and at speed created a drone like a wheel bearing failure.

yep, I get those fart like noises too, I thought it was something to do with the ruby though

I have a gearbox sitting here which I don't need. I was going to put it on ebay but if you can collect from Peterborough and want to make an offer then feel free. It's from a late 2.7 which is the same box as the 2.5.

I find the droning comes from the passenger seat and the farting from the drivers seat.

Now that is funny!

Back to the original question...an '83 gearbox will generally fit, but it wont support the later electronic speedo sender unit, as earlier series cars had a cable-driven speedo.

I think you miss understood me. I was not reffering to the wheel bearings but the drive shaft cv joint bearings, you the 2 shafts from the gearbox to the hubs. There is a cv bearing on each end of each shaft that can wear. If you have tried 2 gearboxes and are getting the same noise, i would suggest its not the gearbox. Its fairly easy to unbolt the drive shafts and get the covers off the joints.

Re Prophead, Its not the CV joints in the propshafts. I have stripped and cleaned them and they are like new inside, no visible wear or play at all. Having "researched" the internet for clues I think my rear wheel bearings on the drivers side need replacing. I am going to change both sides as for £22 each and after only 191K miles a new set wouldn't hurt.

Fair enough. Wasn't clear from earlier posts, fingers crossed hope that sorts it for you.