Thread: Adaptor shaft

Umm, I understand the torque on the MSA output bearing is 226 Nm. What was the torque on the zf - I can't find any reference in my BMW workshop manual.

Originally Posted by workingonit

Umm, I understand the torque on the MSA output bearing is 226 Nm. What was the torque on the zf - I can't find any reference in my BMW workshop manual.

Of the output flange nut, or the max permissible torque the box will withstand?

Originally Posted by Vern

Supporting conversion ring? Huh?

Prob my bad English... By having two flanges and bolting them together, the gearbox and transfer case are held where they need to be. Its easy then to fabricate the conversion ring around the shaft....

Ahh i get ya! As i said, my conversion is done, it just got a broken bit. Which hopefully will be fixed in a couple of weeks one i can find someone localish to cut me a 10 spline

226 torque applied to the flange nut.

My train of thought is:

- the 4BD1t is hard on LRover boxes, and my guess is the boxes often fail (bearings etc) before the SAE10 will.

- the 4BD1t with MSA box is good, but now the SAE10 may fail often as not, and generally along with the adaptor case cracking. No proof yet but the Outcast SAE10 may also succumb in the long run. On this point I could be entirely wrong and Sheldon stuff has the design OK just not the treatment process and as others have said the SAE10 has a long history of reliability when lubed. But has any of that SAE10 history been behind engines like the 4BD1t/MSA combo - for example is the SAE10 of our diameters commonly used in the US for its reliability? Yourself has said you were tired of broken small splines.

- have no argument with your approach. Yours may be the long term solution if SAE10 does not in the long run prove strong enough. But how different are the nut torque values between the zf gearbox and the MSA. If very different then this could be the achilles heal in adapting your approach for the MSA or at least something that needs more consideration. On the other hand if your nose draw bolt can easily cope with 226Nm then great!

I'm not asserting as truth that the SAE10 will break period, but am considering the train of evidence of damage with this engine application and extrapolating to see if there are potential issues.

The long term choice maybe the Sitec method and never need see the inside of your t/c again or carry spare zf extension that are easily field fixable for the occasional inconvenient break.

If people read this and say its trash then I will delete so it is not choking the thread.

Originally Posted by Vern

Ahh i get ya! As i said, my conversion is done, it just got a broken bit. Which hopefully will be fixed in a couple of weeks one i can find someone localish to cut me a 10 spline

Just to put the cat among the pidgeons, why couldn't you use an LT85 gearbox mainshaft and machine it to fit inside your flange Damien. After all it's the correct one for the input gear splines?

Because 28 spline is common in stuff brian

I guess, and not a lot of good s/h LT85 mainshafts. Most of them were fairly worn on the splines from no lubrication.