Drive train angles

[Tdafforn]

Hi All,
Has anyone ever measured the relative outputs of the output flange of the gearbox, and input flange of the differential? Interested in what they are as stock.
tim

[jbuckl]

I can’t say what the factory angle was.

However, for best results in line is to be avoided.

15 degrees is the max recommended operational overall angle from joint manufacturers.

Many installations break the rules though.

Breaking the rule means faster wear & possible extra noise & vibration.

[sujitroy]

The flange on the diff is not centrally placed so I'm assuming the connection between diff and gearbox always will be out of line.
Sujit

[Dorian]

Mine had the RV8 + manual box (Auto now) + BMW rear cross-member/differential and had constant vibration problems until I moved to a split prop-shaft which is more forgiving. I tried everything to help alignment but obviously the BMW bit adds to the potential issues.
Dorian

[Tdafforn]

Mine's a manual rv8 conversion. But seems to be a common problem whatever the engine. Looking at the angles in my car it is not ideal. But suspect it may be the same in triumph powered cars as it would require quite a change in crankshaft angle. Might be why triumph tried cv jointed props.
tim

[Tdafforn]

Mine had the RV8 + manual box (Auto now) + BMW rear cross-member/differential and had constant vibration problems until I moved to a split prop-shaft which is more forgiving. I tried everything to help alignment but obviously the BMW bit adds to the potential issues.
Dorian

when you say split driveshaft do you mean having 3 UJs? or having a driveshaft with 2 UJs and a sliding spline?
tim

[Dorian]

Yes that's right, I have an extra UJ in the middle, a spline to allow for movement and a centre bearing which supports the first section in the gearbox tunnel. The propshaft was made by GKN and I believe was based on one from a LDV van. That was 20 years ago and no problems since then even with other changes in the drive line.
Dorian

[Tdafforn]

Yes that's right, I have an extra UJ in the middle, a spline to allow for movement and a centre bearing which supports the first section in the gearbox tunnel. The propshaft was made by GKN and I believe was based on one from a LDV van. That was 20 years ago and no problems since then even with other changes in the drive line.
Dorian

OK thanks for that.. will try the CV jointed shaft first and then perhaps consider your option. The vibration isn't aweful, just annoying.. but I want to sort it so I can enjoy the RV8 fully..
Tim

[mole42]

I just altered the thread title - it used to be "Drive Chain" which kept making me think I'd strayed onto a Frazer-Nash forum!!

[Tdafforn]

Problem sorted. Fitted a cv jointed prop from rimmers. Judging by the mods it has I suspect it is an SD1 prop.. copes much better with the drive train geometry of the rv8 setup I have. Lovely and smooth. Well chuffed

[wilf]

Glad you got it sorted. Propshaft vibration is very annoying - took me two new propshafts before I finally eliminated it. Kept trying to convince myself that the remaining vibration after fitting the first new shaft wasn't from the shaft, and so left it in position for too long and could not claim anything back on it. The second one (from LD parts) sorted it totally.

[Tdafforn]

Glad you got it sorted. Propshaft vibration is very annoying - took me two new propshafts before I finally eliminated it. Kept trying to convince myself that the remaining vibration after fitting the first new shaft wasn't from the shaft, and so left it in position for too long and could not claim anything back on it. The second one (from LD parts) sorted it totally.

Thanks. Actually consulted a friend who has designed drivetrains for JLR. Him and his friends bet it was the prop geometry clashing with ujs. They thought the CVs should solve it. Now have a nearly new LD prop to sell.
tim