Front drive shaft broken

[C-Mack]

Thanks, Completely understand, best example was every one racing out put new taller springs on the truck to put bigger tire on before the rest it was fully test and hashed changes need to make it work correctly long term.

Exactly, modifications can be a slippery slope of issues at times as you discover additional modifications are required to fix the compromises of the first modifications, which lead to more and so on, etc... The more money you invest into a project can make you more reluctant to abandon previous modifications which creates a type of tunnel vision or vicious cycle until one day out of frustration you realize it has all been a bit of a let down.

Sure, I’m painting an extreme scenario above just as an example, but as most folks know, doing your homework and having a good understanding of the pros & cons you can typically avoid most of the hassle. That’s why I think this forum is so important for Grenadier owners as you can learn not only what you “can do” but equally, if not more importantly, what “not” to do at times.

 

[angstorms]

We really need this picture for Ineos axels. I know c-mack will recognize this is for Dana axel. Has anyone really measured if Pinon angle was zero what caster angles relationship really is for the Carraro axels and documented it.

This show ratio of Pinion angle vs Caster angle, this would help these discussions. since this what we moving if we adjust length of lower or upper control arms around the center of the axel. We need this for picture for the Grenadier, then it we have a key inputs for really a math problem for a four link suspension. Right now we have fixed length arm the upper, and lower is varied to increase caster angle, but when you do increase the caster angle pinion angle also changes which really what nicely people are trying to get across. You could do the same and set the bottom link to fixed length and then pull in or push out top link and it will change caster and pinion angle.

T

 

[C-Mack]

We really need this picture for Ineos axels. I know c-mack will recognize this is for Dana axel. Has anyone really measured if Pinon angle was zero what caster angles relationship really is for the Carraro axels and documented it.

View attachment 7883234

Humbly, I couldn’t tell you what sort of axle the illustration represents but thank you for sharing as it perfectly illustrates the hard fixed relationship between caster/pinion we all should be aware of. Would love to know what engineering considerations the IA/Carraro teams went through to give us the present setup on the Grenadier?

 

[Zimm]

when the rig is getting an alignment, pop off the shaft and get a reading.

 

[C-Mack]

Take some caster/pinion measurements at various axle articulation points to see how things change through the range of suspension travel. Or better still, take measurements at the simulated ride heights of the most common springs on offer such as stock, 1.2”, 1.7”, 2.5”, etc… to help give folks a heads up on the pinion/caster changes they can expect to encounter.

Surely some of the bigger/well known aftermarket shops currently doing lifts on the Grenadier could remove the front stock springs during an install on one of their product test vehicles and use a couple of tall jack-stands under the axle to positioned at the different spring heights and take some basic measurements? That would be very kind and helpful of them for the sake of public knowledge.

 

[TahoeGren]

Yeah would be great to get true measurements for all those variables with the shaft off for accuracy. I think lifting at the frame to simulate various lift heights could work too.

Looking at my notes from a while back, I measured the pinion was pointing down 2.4 degrees with caster at the nominal 2 degrees and stock springs. I used the face of the bolts as I didn’t take the driveshaft off, so not super accurate. I measured using a Klein angle gauge.

 

[Dokatd]

Best update I have at the moment is that I am in discussions with an alternate shop. Tom Woods is still on the table, but their capabilities may not meet our needs. I will update once something of consequence happens.

 

[Zimm]

Best update I have at the moment is that I am in discussions with an alternate shop. Tom Woods is still on the table, but their capabilities may not meet our needs. I will update once something of consequence happens.

boo tom woods.

 

[Dokatd]

boo tom woods.

Well, it's kind of understandable to a degree. They currently lack some of the required fixturing. I have offered to front the money to buy what's needed. Conversations are still being had.

 

[Zimm]

Well, it's kind of understandable to a degree. They currently lack some of the required fixturing. I have offered to front the money to buy what's needed. Conversations are still being had.

They make crap for every brand out there, I though. I have one in my 40 since I 5 speed swapped it. What about this is causing an issue? I'd expect they had all the apparatus they needed, and the hold up would be lack of potential market.

 

[Dokatd]

They make crap for every brand out there, I thought. I have one in my 40 since I 5 speed swapped it. What about this is causing an issue? I'd expect they had all the apparatus they needed, and the hold up would be lack of potential market.

The pinion side is the primary problem. For practical purposes it needs to remain a Rezeppa joint. Tom Woods does not have the capabilities to build and balance a shaft with a Rezeppa.

 

[Dokatd]

As a side note, I'm not yet convinced that there isn't a problem with the compound used on the Ineos boot. Or possibly there is a heat issue. Or maybe a bit of both. My Terra Flex version of the joint is holding up well with no signs of failure yet.

 

[Zimm]

The pinion side is the primary problem. For practical purposes it needs to remain a Rezeppa joint. Tom Woods does not have the capabilities to build and balance a shaft with a Rezeppa.

I never really moved off of anything more then 50mm needing a cut and turn for reliability. I just don't see it happening from anecdotal experience, but, I'm open to rooting for good attempts. I didn't buy this rig planning on 37's anyway, so I'm not that disappointed.

 

[anand]

For what it's worth apparently there's a large name Jeep drive shaft company that has a front driveshaft that's been tested on the Grenadier, I'll try to have specifics this week; but from what I was told this weekend it is near or ready for sale.