Prop question

[felstmiester]

I fitted sammy axles to my 410 the other week. After completion I took it up the round and found that in first and second when turbo kicks in ( Isuzu 1.5 Derv ) I get a vibration through the drive train. At first it was thought to be axle wrap but I'm sure it's not as the spring perches I've made at bigger than standard.
But what I did have to do was cut the rear prop down shorter at the splines on the male side and the female because the diff on the sammy axle is slightly longer. I'm now thinking I may not of cut enough and this is why I'm getting the vibration.

[ferris]

I may be wrong but i'm pretty sure that prop shafts have to be balanced. There is a indent on the male and female side and you have to line these up when you put the shaft together. So by cutting it you may have unbalanced it and this may be causing the vibrations.

[ScottieJ]

You could have just bought some samurai prop shafts, they are shorter

Did you modify the transfer box mounts at all?

When welding the spring perches on did you make sure that you set the pinion flange angle correctly? It needs to be parallel with the Tbox output within 1-2degrees. Tilting it down 1-2degrees down can also help reduce vibes as there will be a tiny amount of axle wrap when under load I.e. driving and this will mean the flanges end up parallel while driving along. If the angles are out then the UJs will not be working together (in phase) and it will give you bad vibes and cause premature failure of the UJs.

[felstmiester]

I have got the sammy props but the holes on the sammy ones are different to the centres of the flange on the transfer box so I used sammy back half that bolted to flange on sammy diff and 410 front that bolted to transfer box. As for prop angle ill take a pic and post it up. I would have thought its ok.

[felstmiester]

Looking at some of the angles ive seen people run probs i wouldn't of thought this is the problem????

[Edweird]

There's so many things wrong in that picture!

The springs are knackered, that prop angle looks really bad. The axle looks like it's rotated and the T-box is too low.

[felstmiester]

There's so many things wrong in that picture!

The springs are knackered, that prop angle looks really bad. The axle looks like it's rotated and the T-box is too low.

The springs are fine. I can kinda see where your coming from cos in the pic they do look quite flat but there not. they're actually rascal rears.

The transfer box is just in the standard possision not tha you can see that in the pic so not sure how you came to that conclusion.

The prop angle is the reason i posted up the pic but i have driven sj's and sammy's with spoa that are running ridiculous prop angles and they didn't do what mine is doing. The torque of the engine prob aint doing it no favours.

[felstmiester]

Ah!! Could it be that ive use two different halfs of the prop?? If sammy UJ's are different to 410 UJ's then the back half of the prop being a sammy and the front half being 410 would throw it out would it not?? Didn't think of that when i done it.

[Darrell]

I'm afraid it looks like the last one
But I dunno

Pinion angle.jpg (44.78 KiB) Viewed 6913 times

Did you weld the new perches parallel with the original ones ???

[felstmiester]

Ill take a pic the transfer box end as well yeah I make ya right it does look like the last one but only at one end. The transfer box end looks strait lol.