Rear Prop-shaft angle 1120 AF

[Geo.Lander]

Hi, Does anyone have the specs on the rear propshaft angle torerances? Mine is looking a little extreme..

 

[VerMonsterRV]

Hi, Does anyone have the specs on the rear propshaft angle torerances? Mine is looking a little extreme..
View attachment 781220

I have to say I think it might be a little too much. I think you have the same springs we do though. It looks like you only have the thin block beneath the springs on place? When I put in our new front ones they were high. A quick run down a washboard road settled them down a lot. How much does your truck weigh now? I'm guessing a lot lighter than when you finish and load up.

 

[charlieaarons]

From my recollection only, the angles are supposed to be equal and opposite (and of course minimized) for lowest probability of severe vibration.
In particular, your differential pinion is angled up quite a bit relative to the transfer case output.
The usual way of adjusting that is a wedge at the bottom of the spring pack. For light vehicles they are sometimes made of aluminium, but in the case of a medium or heavy truck, obviously should be steel.
If a driveshaft shop is available, you should consult them.
In these sorts of situations, greasable U-joints along with short servicing intervals are desirable. In desperate situations, custom built CV (“constant velocity”) joints are necessary, basically 2 U-joints in series with a low friction usually greasable ball in between that allows ery low friction articulation between the 2 closely adjacent U-joints.
AFAIK, that’s pretty much it.

 

[Cois]

Maybe this can help a bit. Extract from the Mercedes equipment directives.

 

[Geo.Lander]

I have to say I think it might be a little too much. I think you have the same springs we do though. It looks like you only have the thin block beneath the springs on place? When I put in our new front ones they were high. A quick run down a washboard road settled them down a lot. How much does your truck weigh now? I'm guessing a lot lighter than when you finish and load up.

I need to get her on the scales actually, I presume she is about 7000kgs now,. I expect about 8500 when fully loaded and built but not a lot of that will be over the rear... I am wondering how the rear got so high actually..

 

[Geo.Lander]

Maybe this can help a bit. Extract from the Mercedes equipment directives.

Thanks for this!

 

[Iain_U1250]

It should be OK, provided everything is lined up properly. Make sure the two flanges are parallel, and the propshaft is in phase. Get either wrong and you will have a problem.

 

[Geo.Lander]

From my recollection only, the angles are supposed to be equal and opposite (and of course minimized) for lowest probability of severe vibration.
In particular, your differential pinion is angled up quite a bit relative to the transfer case output.
The usual way of adjusting that is a wedge at the bottom of the spring pack. For light vehicles they are sometimes made of aluminium, but in the case of a medium or heavy truck, obviously should be steel.
If a driveshaft shop is available, you should consult them.
In these sorts of situations, greasable U-joints along with short servicing intervals are desirable. In desperate situations, custom built CV (“constant velocity”) joints are necessary, basically 2 U-joints in series with a low friction usually greasable ball in between that allows ery low friction articulation between the 2 closely adjacent U-joints.
AFAIK, that’s pretty much it.

Nice, I actually only managed to make sense of this after reading the PDF @Cois added!

 

[Geo.Lander]

It should be OK, provided everything is lined up properly. Make sure the two flanges are parallel, and the propshaft is in phase. Get either wrong and you will have a problem.

Really helpful vid thanks @Iain_U1250 !
I at now have a basic understanding of this topic

 

[Geo.Lander]

seems I have the big blocks here.. I am wondering how much extra weight I will be adding during the build out. I have all the materials in storage in the basement so I suppose I can calculate this circa at 1000kgs just in materials.. I am still thinking maybe I should reduce this spacer size..