What are rules for flat tow c4 with twin stick dana 20....

[RustBeltRefugee]

Sorry, I didn't literally mean that the input shaft was lubing the 'case, but that stuff that spins with it does. The high speed gear on the front output shaft turns with the input shaft as you note, but that also means that it stays stopped with the input shaft as well. And with the trans in park the input shaft (and therefore the high speed gear) can't turn.

However that link is helpful. The front output sliding gear will turn if the front hubs were locked, so it would make sense that it would lube the 'case well enough. Again, for me personally the risk of burning something up while flat-towing isn't worth the little bit of labor savings to not drop the rear driveshaft. But at least there is some basis for saying leaving the hubs locked will work.



Drag from where? The unlocked front hubs? There's way more drag in the front axle, front differential, front driveshaft and transfer case then there is in the hubs. None of that will turn if the hubs are unlocked.

Sorry, the Dana 44 hubs look like they disengage enough to not cause much if any drag. Just me but if I was getting under the truck to disconnect the rear then I would probably just go ahead and disconnect both driveshafts. Because once I start worrying about things I usually start worrying too much. Otherwise I would just lock the front hubs and put the transfer case in neutral and leave the driveshaft connected. I would have to do a search but I think I have read about members successfully using the latter method.

Doing a search here before flat towing would be a good idea before flat towing. Flat towing seems to inherently have risks but it has it's merits. There is a lot of information regarding flat towing aside from transfer case and transmissions concerns on this site.

 

[chuck]

OR install rear hubs

 

[ntsqd]

I still think Chuck's first post is the best way to do it w/o spending a pile of cash.

BT, DT trying other options and had the hurt transfer-case to deal with.

After seeing the ripple-effect carnage from MISF's failed Warn rear hub (Warn FF conversion) there's no way I'd trust one of them. His failure happened making a left turn on a city street. No doubt what stressed it almost to failure occurred off-road, but a simple left turn cost him one Warn hub, two axle shafts, and a D60 Detroit.

 

[chuck]

I was not aware of this problem, do you know the order of damage?

 

[ntsqd]

It was an old Warn FF conversion kit used to build a 5X5.5 Dana 60 rear way before there were any aftermarket 5X5.5 rear wheel hubs. Used Warn Locking hubs instead of drive slugs (was a later option, but he was an early adopter). A just sub 8000 lbs truck taxed them too much when used in the rear. One failed with the predictable Detroit failure, but in the process it took out one axle and damaged the other to where using it was iffy.

 

[chuck]

I can see the hub failing, weak link and they were kind of hard to get fully in gear. Do you know what failed in the locker and how that effected the axles? Assuming the locker went next how did that cause axle damage. I am not questioning what happened just wandering how all that came from a hub failure. You may not know and that is fine, I just like to know stuff.

 

[Ol'Blue]

I just disconnect the rear of the driveshaft and sling it up under the body. Tape the joints real good. Its worth the 10 minutes and piece of mind.

 

[ntsqd]

I can see the hub failing, weak link and they were kind of hard to get fully in gear. Do you know what failed in the locker and how that effected the axles? Assuming the locker went next how did that cause axle damage. I am not questioning what happened just wandering how all that came from a hub failure. You may not know and that is fine, I just like to know stuff.

It has been a while since this happened, so I'm having to pull it out of memory. Pretty much everything inside the Detroit that would have been under load in the middle of a turn was trashed when the locking hub let go. Far from the first time a Detroit has been kilt dead like that. Seems like it is the most common death of a Detroit. The hub letting go also destroyed the splines on both axles and I think that the near-side axle (one with the failed hub) also had cracks in it.
I figured that was the case, no worries.

I just disconnect the rear of the driveshaft and sling it up under the body. Tape the joints real good. Its worth the 10 minutes and piece of mind.

I've spent some time looking for a companion flange to replace the pinion yoke. Can get one for the drive-shaft, but haven't found one for the pinion. Then it would be 4 bolts and no worries about the caps getting away. So far what little I've found has been expensive if this is the only reason for converting.