944 turbo touque tube front spline measurement needed

[Dan944t]

hi guys,

need a strange bit of knowledge if anyone knows or can figure out past what I was going to try.

when I pulled my engine few years back the tourque tube was a pig to pull out of he bell housing, and I noticed later on the following year that I’m pulling from the rear to pull te front splines out of the clutch and bell housing, i seem to have pulled the torque tube casing itself back a bit obviously sliding over the bearings inside thus making the front of the splines protrude further forward and at the rear its obviously gone forward into the tube.

By how much im not sure at a guess possibly 80mm plus?

question is does anyone know the measurement say from the front tube flang to the very front of the spline, so I can press it back in?

i could muck about with trial and error but obviously once the engine is in the bay it’s a no go getting in the and knocking it back, and I don’t fancy keep putting it in and out as not to disturb the clutch allighnment let alone the frustration it will cause.

ive thought of measuring how deep the spline hole is through the bell housing and working it out that way but wouldnt want it to come up short or long once I’m trying to join the gearbox spline at the back.

then I thought I could measure from the back as if the tourque tube flang was bolted flat on the gearbox and leve a 10 mm gap between the two splines?? It’s just that I can’t remember the gap it had now as it was a few years ago since I’ve pulled the engine and box from the car.

https://imgur.com/a/WBSbz3J

atb
Daniel ??

 

[scam75]

I think the TT's are all standard, so if you find someone with one out a car should be no worries. Maybe try a couple of breakers and see if one is kind enough to measure for you? You could also buy a 2nd hand one, but obviously risks involved in that and if yours is good may not be necessary. I think these guys offer a TT rebuild/exchange service so may be a good starting point?

http://www.rgaporschelondon.co.uk


Stuart

 

[bmnelsc]

I'll apologize in advance if this is too much information but perhaps others will find it useful.

The Haynes manual gives the measurement from the rear flange where the TT mounts to the transaxle - probably because it is easier to measure consistently from that end. This is from the 924 manual for 4 speed and O16J 5 speed transmissions. Place a straight edge across the torque tube "bell-housing" (transmission end) and measure from the straight edge to the end of the drive shaft. Should be a 13.5 +/- .5 mm gap between the straight edge and the end of the drive shaft. I haven't seen a measurement for this anywhere else. If you look at the shop manual for transmission removal it shows the drive shaft/transmission input shaft clamping sleeve with the clamping bolts on either side of the torque tube bell housing/transmission case joint so having the end of the driveshaft stopping short of the mounting surface for the bell housing makes perfect sense.

Remember that the drive shaft must go thru the clutch splines and into the pilot bearing on the flywheel AND the groove on the other end of the shaft must align with the cross bolt on the drive shaft to transmission input shaft clamping sleeve so I would take the measurement above as a starting point - you may have to slightly adjust the for/aft of the drive shaft in the torque tube to get your clamping sleeve to fit regardless. Be confident that when the tube is bolted up on each end and the clamping sleeve is properly aligned, the drive shaft will be far enough into the flywheel pilot bearing - unless your drive shaft has shrunk

Oh - the instructions I have seen regarding positioning the drive shaft in the torque tube dictate the use of a soft faced hammer to tap it one way or the other. The drive shaft is a slip fit to the inner races of the torque tube bearings so it should move around without much difficulty- the outer races of the bearings are friction fit to the tube by virtue of the rubber insulators that isolate the bearings from the tube (for noise and vibration damping) so moving these back and forth requires tools so it is not likely that you moved these around accidentally.

 

[Dan944t]

Sorry for the late response Stuart ! I’ve been working on the engine rebuild today.

thanks for the quick response and the info ??

 

[Dan944t]

I'll apologize in advance if this is too much information but perhaps others will find it useful.

The Haynes manual gives the measurement from the rear flange where the TT mounts to the transaxle - probably because it is easier to measure consistently from that end. This is from the 924 manual for 4 speed and O16J 5 speed transmissions. Place a straight edge across the torque tube "bell-housing" (transmission end) and measure from the straight edge to the end of the drive shaft. Should be a 13.5 +/- .5 mm gap between the straight edge and the end of the drive shaft. I haven't seen a measurement for this anywhere else. If you look at the shop manual for transmission removal it shows the drive shaft/transmission input shaft clamping sleeve with the clamping bolts on either side of the torque tube bell housing/transmission case joint so having the end of the driveshaft stopping short of the mounting surface for the bell housing makes perfect sense.

Remember that the drive shaft must go thru the clutch splines and into the pilot bearing on the flywheel AND the groove on the other end of the shaft must align with the cross bolt on the drive shaft to transmission input shaft clamping sleeve so I would take the measurement above as a starting point - you may have to slightly adjust the for/aft of the drive shaft in the torque tube to get your clamping sleeve to fit regardless. Be confident that when the tube is bolted up on each end and the clamping sleeve is properly aligned, the drive shaft will be far enough into the flywheel pilot bearing - unless your drive shaft has shrunk

Oh - the instructions I have seen regarding positioning the drive shaft in the torque tube dictate the use of a soft faced hammer to tap it one way or the other. The drive shaft is a slip fit to the inner races of the torque tube bearings so it should move around without much difficulty- the outer races of the bearings are friction fit to the tube by virtue of the rubber insulators that isolate the bearings from the tube (for noise and vibration damping) so moving these back and forth requires tools so it is not likely that you moved these around accidentally.

This is perfect ???? this should get me there Thankyou very much, great info here and thanks for your long rightup, it makes sense, I’ll try getting under the car tommorow and see how far out it is and hopefully by the end of the week I will be putting this info to good use ??????

thanks again!
Daniel ??