934 axle interference question.

[L.R.S.]

A couple samples of cars I've recently prepped-



Tatum Blackwidow, Tatum mid board 934 hubs.  Outside axle clip is beat to sh!t.  No limit straps on this car, axle may be a little short on this side (opposite hub side sprial clip was fine).  



Gen 3 Funco, micro stub.  Trans side spiral clip fell off and was sitting in the cup.  No way to know how long it's been off, first time I've prepped this car for my client.  Same CV had 5 out of 6 CV bolts finger tight.

This is what prep is all about- find it before it's a problem and ruins your vacation.  This car also has the grease plates, which I'm absolutely NOT a fan of.  It has nothing to do with me wanting more prep jobs, I've had an 8 car waiting list all year and still do as of today.  Pumping grease into the CV gives a false sense of 'it's prepped' so I can go another season.

 

[r3meyer]

A couple samples of cars I've recently prepped-

View attachment 47149

Tatum Blackwidow, Tatum mid board 934 hubs.  Outside axle clip is beat to sh!t.  No limit straps on this car, axle may be a little short on this side (opposite hub side sprial clip was fine).  

View attachment 47150

Gen 3 Funco, micro stub.  Trans side spiral clip fell off and was sitting in the cup.  No way to know how long it's been off, first time I've prepped this car for my client.  Same CV had 5 out of 6 CV bolts finger tight.

This is what prep is all about- find it before it's a problem and ruins your vacation.  This car also has the grease plates, which I'm absolutely NOT a fan of.  It has nothing to do with me wanting more prep jobs, I've had an 8 car waiting list all year and still do as of today.  Pumping grease into the CV gives a false sense of 'it's prepped' so I can go another season.

No sure I agree... I treat my cv's like Schrodingers Cat.  lol

 

[J Alper]

Obviously I have micro stubs and not mid boards but just trying to picture what you are saying here. So you are pulling the hat and boot all off together. The boot just slides off of the splines. And then you put it back together the same way?

ON the midboards I have, you have 12 5/16 bolts, the 5/16 bolts will hold the hub onto the plate, you can get to all the bolts with the boot still on, after the 5/16 bolts are unbolted the hub will come right off the car. 934 are heavy so if you put them back on with the trans cv's and axle already installed, you need someone to hold the star straight and someone to hold the hub,  

 

[Sean@Weddle]

I am no expert on this subject, but I feel like I've had a decent understanding of how these work over the past years.

My understanding is that you want the longest axle possible, allowing for 1/4"-3/8" of freeplay at the shortest distance between the hub and trans flanges as the suspension cycles. Is that incorrect? ( @L.R.S. looking at you here)

If you have too short of an axle, and you have clips holding the CV joints on each end, the inner star can be pulled out of the outer joint at full droop if your shocks or limits straps allow too much angle. This is obviously not good. Too much freeplay would also allow for the axle to bounce between the flanges/cups and beat up the end of the splines. Another issue is if the splines are too short, the inner star can slip off the inner portion of the splines and loose drive. (Tagging @L.R.S. in this one again for fun)

If you have too long of an axle, it will get bound up between the flanges as the suspension cycles, thus mushrooming the end of the axle and putting load on the hub and trans drive flanges. Not good for the trans drive flange bearings at all.

I have always told customers to cycle the suspension without shocks/springs, measure at the shortest possible distance, then subtract 1/4"-3/8" for proper axle length. (This is how it was explained to me by others with far more experience than myself over the years as well)

 

[Rockwood]

To add: cycle it by hand.  Your 3T jack may/may not notice the slight interference in the axle... :biggrin: