Re-rebuilt transmission, built my transmission again Options

[panayotisnikas]

Hello everybody ,
recently I built a 5 speed gearbox and flipped it to go in a beetle,
Replaced the rear input shaft bearing that was exploded, first gear dog teeth and synchro ring . Also diff bearings seals etc.
Everything was rather ok except a noise around 2500 on deceleration, meaning it made a kind of sound when taking my foot rapidly off the gas. Barely audible so I didn't bother too much.
It also made a noise when shifting from 1st to 2nd the whole while the clutch was pressed it reminded me of the whine reverse does when you take your foot off the gas,
Again no big deal.

Until the input shaft bearing had a ball break in half and the transmission was noisy.
Bearing was a chiniese off the map brand so we can assume it was the fault since balls really rarely break.
So I pulled the transmission off the car and noticed that the roller bearing for the pinion didnt have a very happy looking race and the input shaft Roller race wasn't perfect as well.

I replaced all 3 bearings with genuine porsche ones.
meanwhile I took a close look to the ring and pinion. They are in ok shape but not perfect, shiny, no marks but some teeth have some stain looking marks, you can't catch them with your nail but can notice them specially with a magnifying glass.

I assembled the gearbox , installed it on the car and the results are:
1) You almost can't notice any sound when clutch let off in neutral, makes some very minimal noise that you have to twist your mind to hear, but again its a gearbox not a clutch.
2) strange sound from 1st to 2nd disappeared
3 sound when letting gas off at 2500 is better cold but didn't dissapear.

Any ideas?

[ctc911ctc]

I would study the Dr. Evil DVDs on this topic. They are authoritative and informative. You will be able to diagnose those ills.

I bought the set of DVDs and have not regretted it.

Hello everybody ,
recently I built a 5 speed gearbox and flipped it to go in a beetle,
Replaced the rear input shaft bearing that was exploded, first gear dog teeth and synchro ring . Also diff bearings seals etc.
Everything was rather ok except a noise around 2500 on deceleration, meaning it made a kind of sound when taking my foot rapidly off the gas. Barely audible so I didn't bother too much.
It also made a noise when shifting from 1st to 2nd the whole while the clutch was pressed it reminded me of the whine reverse does when you take your foot off the gas,
Again no big deal.

Until the input shaft bearing had a ball break in half and the transmission was noisy.
Bearing was a chiniese off the map brand so we can assume it was the fault since balls really rarely break.
So I pulled the transmission off the car and noticed that the roller bearing for the pinion didnt have a very happy looking race and the input shaft Roller race wasn't perfect as well.

I replaced all 3 bearings with genuine porsche ones.
meanwhile I took a close look to the ring and pinion. They are in ok shape but not perfect, shiny, no marks but some teeth have some stain looking marks, you can't catch them with your nail but can notice them specially with a magnifying glass.

I assembled the gearbox , installed it on the car and the results are:
1) You almost can't notice any sound when clutch let off in neutral, makes some very minimal noise that you have to twist your mind to hear, but again its a gearbox not a clutch.
2) strange sound from 1st to 2nd disappeared
3 sound when letting gas off at 2500 is better cold but didn't dissapear.

Any ideas?

[ctc911ctc]

http://www.914world.com/bbs2/index.php?showtopic=318209

Above is a Dr. Evil Link

[porschetub]

[quote name='panayotisnikas' date='May 8 2020, 12:21 PM' post='2812731']
Hello everybody ,
recently I built a 5 speed gearbox and flipped it to go in a beetle,
Replaced the rear input shaft bearing that was exploded, first gear dog teeth and synchro ring . Also diff bearings seals etc.
Everything was rather ok except a noise around 2500 on deceleration, meaning it made a kind of sound when taking my foot rapidly off the gas. Barely audible so I didn't bother too much.
It also made a noise when shifting from 1st to 2nd the whole while the clutch was pressed it reminded me of the whine reverse does when you take your foot off the gas,
Again no big deal.

Until the input shaft bearing had a ball break in half and the transmission was noisy.
Bearing was a chiniese off the map brand so we can assume it was the fault since balls really rarely break.
So I pulled the transmission off the car and noticed that the roller bearing for the pinion didnt have a very happy looking race and the input shaft Roller race wasn't perfect as well.
[quote]

Appears you haven't contacted the best transmission guy around,sorry to sound like an ass but you tend not to take good advise well (IMG:style_emoticons/default/dry.gif) and just carry on doing your OWN thing,good luck on this track.
My own 5 speed isn't without issues but has no noise @ any RPM ,for example are your CV shafts set up right ? there are other factors ,the 901 box isn't easy....as they say ''fine when working''.
Rant over.

[panayotisnikas]

[quote name='porschetub' date='May 8 2020, 05:29 AM' post='2812799']
[quote name='panayotisnikas' date='May 8 2020, 12:21 PM' post='2812731']
Hello everybody ,
recently I built a 5 speed gearbox and flipped it to go in a beetle,
Replaced the rear input shaft bearing that was exploded, first gear dog teeth and synchro ring . Also diff bearings seals etc.
Everything was rather ok except a noise around 2500 on deceleration, meaning it made a kind of sound when taking my foot rapidly off the gas. Barely audible so I didn't bother too much.
It also made a noise when shifting from 1st to 2nd the whole while the clutch was pressed it reminded me of the whine reverse does when you take your foot off the gas,
Again no big deal.

Until the input shaft bearing had a ball break in half and the transmission was noisy.
Bearing was a chiniese off the map brand so we can assume it was the fault since balls really rarely break.
So I pulled the transmission off the car and noticed that the roller bearing for the pinion didnt have a very happy looking race and the input shaft Roller race wasn't perfect as well.
[quote]

Appears you haven't contacted the best transmission guy around,sorry to sound like an ass but you tend not to take good advise well (IMG:style_emoticons/default/dry.gif) and just carry on doing your OWN thing,good luck on this track.
My own 5 speed isn't without issues but has no noise @ any RPM ,for example are your CV shafts set up right ? there are other factors ,the 901 box isn't easy....as they say ''fine when working''.
Rant over.
[/quote]


Hello, I didn't get the part " you tend not to take good advise well" I have contacted dr evil and waiting for an answer. Seeking opinions is the reason forums exist . By now we all know who is the best at what, but still creating topics with the hope that the next person in our position has the answer ready.

The last question of mine you answered was about the input shaft roller, I contacted dr evil as you suggested and this is the reason I state I used genuine porsche bearings since he wasn't extatic about another bearing being used.

Well if the noise I am hearing is the crown and pinion getting old there isn't really much to do, just be careful with it and change oil more frequently , until a better set is obtained .

This is what I would like to know.