Dual double cardan joint 1350 front driveshaft and factory CV discussion.

[bamanuke]

I was sent a picture by the company that had carried out the lift on the Grenadier belonging to George Ratcliffe himself. I guess that if he was to suffer any problems, it wouldn't be a big problem regardless.

The amount of fails involved, in my view could well be down to mistakes in fitting. I can see how a boot could easily be damaged. Or am I just wishful thinking?

you are.

 

[255/85]

Regarding case IG I have not actually seen any lifted vehicle but it is possible that original prop shafts (Am. drive shafts) don't have much reserve strength. But where in this axle/propshaft construction is the elongation reserve for suspension travel (traditional sliding joint)? Is it possible that this is not enough for the lifted vehicles and causes these damages? If so, this could be solved with additional adjustiing plate between flanges on one end of prop shaft.

Uptravel isn't usually affected with simple spring lifts as the axle bump stops remain in place. Generally speaking here's no additional compression or shortening to the driveshaft. If the splines of each half of the DS are too short from lift or droop or bad design then rotational deviation can occur as wear is focused over less spline.

I asked in the other thread why we see failure in the rear CV and not at the differential. Ignoring that stock operating angles appear imho to be too great we're left with:

1) Lift install errors that compromise the boot. Does rear boot failure occur on stock vehicles?

2) Lifted vehicles without caster correction exacerbate CV angles at the transfer case more than at the diff especially when driven over long distances.

3) The cast iron differential likely has inner and outer pinion bearings. The front output shaft of the aluminum transfer case may not have as much support allowing shaft runout or even case flex.

4) Mismatched angles between the front pinion and the front transfer case output from the factory. I have been informed here that this is not as much of a consideration with CVs vs U-joints but whichever is more extreme will show wear first. @Bodhi’s Grenadier illustrates this with the dual double cardan set-up I think. At high torque and speed (7th & 8th gear) he's got driveline resonance that would be unnoticeable at crawl speeds. The input and output angles are mismatched...imho...with the more severe angle at the transfer case. I hate to mention this possibility as the solution is not U-joints but better CVs (others have said this already) or a new front axle housing or both!

 

[255/85]

I was sent a picture by the company that had carried out the lift on the Grenadier belonging to George Ratcliffe himself. I guess that if he was to suffer any problems, it wouldn't be a big problem regardless.

The amount of fails involved, in my view could well be down to mistakes in fitting. I can see how a boot could easily be damaged. Or am I just wishful thinking?

What Ratcliffe has and what we bought may be two entirely different animals.

 

[MrMike]

4 days of moderate to light offloading. ~400mi or so.

I am going back to stock!

Why not order the AU kit, slightly lower front, without issues

 

[NQ94]

For the vehicles that have shaft failure. Has the oil and oil quality been checked in the transfer case and front diff. When the shafts have failures it would be a good idea to drain the oil in the t/case in a clean clear container for inspection and maybe a sample for analysis. Replace the oil. From previous experience with trucks and machinery driveline failures it is common to have secondary unnoticed damage in and around the drive line or transmission. In some of the worse cases there have been minor to severely cracked housings that go unnoticed for sometime and develop into leaks or seals that continue to leak after multiple replacements or new odd noises and vibrations after initial repairs.

 

[Jean Mercier]

I was sent a picture by the company that had carried out the lift on the Grenadier belonging to George Ratcliffe himself. I guess that if he was to suffer any problems, it wouldn't be a big problem regardless.

The amount of fails involved, in my view could well be down to mistakes in fitting. I can see how a boot could easily be damaged. Or am I just wishful thinking?

I also think you are
In my opinion, if there are some fast failures on raised cars (and of course here INEOS could refuse warranty repair) AND on some unmodified cars (no discussion possible about warranty!), this doesn't seem good for the long term.
Reliability seems to be quite poor for that driveshaft. I will (didn't do it yet) check mine.

 

[Zimm]

I also think you are
In my opinion, if there are some fast failures on raised cars (and of course here INEOS could refuse warranty repair) AND on some unmodified cars (no discussion possible about warranty!), this doesn't seem good for the long term.
Reliability seems to be quite poor for that driveshaft. I will (didn't do it yet) check mine.

I didn’t notice any untouched cars failing. Apparently the cv choice was half baked like much of the truck but, it think it works if unaltered so I’m not gonna fret it unless there’s there’s something definitive. This hasn’t proven to be endemic yet.

 

[DrahthHunter]

View: https://youtu.be/68OnPC5TgsI?si=rJ8IGB-3z_ykXnOy

View: https://youtu.be/8HP387BhRk8?si=-4N1D5syNy-RAG39

are they selling these yet?

 

[Asnes]

are they selling these yet?

No, not yet

 

[DrahthHunter]

No, not yet

Thank you sir

 

[Tom109]

Seems to be a must do modification at this point....

I think it prudent for a little more (IA) investigation and (IA + aftermarket) development time.

While I was originally happy with the CV design as I wouldn’t have to replace DC centering balls, now I’m a little concerned.

 

[255/85]

I think it prudent for a little more (IA) investigation and (IA + aftermarket) development time.

While I was originally happy with the CV design as I wouldn’t have to replace DC centering balls, now I’m a little concerned.

Or have to worry about matching pinion/TC output shaft angles when fitting suspension lifts.

 

[Bodhi’s Grenadier]

are they selling these yet?

Please DM me for more info. I have significantly minimized/eliminated harmonics with adjustments to the angles. You can order now if you like!

 

[Shroomy]

Please DM me for more info. I have significantly minimized/eliminated harmonics with adjustments to the angles. You can order now if you like!

DM sent

 

[Zenbox]

DM sent as well. If the harmonics issue has been resolved, I am definitely interested in ordering one. Thanks!

 

[LeeroyJ]

I've had the Eibach lift springs with 35" tires for about 7500 miles now. I just checked mine and they look fine to me, do others agree?

 

[Bodhi’s Grenadier]

I've had the Eibach lift springs with 35" tires for about 7500 miles now. I just checked mine and they look fine to me, do others agree?

They look fine

 

[Tom D]

I've had the Eibach lift springs with 35" tires for about 7500 miles now. I just checked mine and they look fine to me, do others agree?

Realy interesting, why are some breaking quickly?…different batch?

 

[bamanuke]

I've had the Eibach lift springs with 35" tires for about 7500 miles now. I just checked mine and they look fine to me, do others agree?

had the about the same mileage on my lift springs when my front driveshaft failed.. I'm running stock 17's and am loaded a little heavy with a 55gt fridge and slide, ~180lb RTT, small awning and the alu-cab cross bars/mounts. Here's my newly installed replacement. Caster was at .9 and 1.0 (hunter machine). The difference between ours is considerable. Now just to figure out why (Thanks J.V., for letting me pick your brain). I'll start with removing the weight , then changing back to stock springs. DC after the warranty period. Also plan to install the Teraflex Jeep JT Rzeppa on the failed DS for a spare. Any other suggestions would be appreciated.