adaptor l480e auto box to np205transfer case

DarrenWebster303 wrote: Alister, I cut the rear spring saddles off & rotated the pinion up to point at the back of the transfer case. A double cardan joint on the front of the shaft & it is as smooth as silk. I also cut a rectangle out of the rear diff cover & welded it back in upside down to raise the fill level so the pinion bearings don't hate me.

More oil to the wheel bearings as well???

After denting the front sheetmetal cover in enough to hit the crown wheel I fitted heavy duty plate covers and as the oil levels/filler plugs were totally wrong/too high for our application I fitted another plug at the correct level, they are 8 mm thick steel plate so can easily take a threaded hole at the correct level. The best bit though is they have drain plugs so oil can be changed easily if contaminated.
Having drainplugs doesn't negate the need to take the covers off and retorque the crownwheel bolts at the correct intervals though, they do come loose over time, on my front diff they have been fingertight.
Russ yes you can run higher oil levels but would be wary of making them too high, might put too much on the axle seals.

Guys
The point of a uni joint is to allow two PARALLEL shafts that are not in the same plane to be connected together and transmit power. Too far out of parallel and you get vibration.





Turning the nose of the diff upwards means that the shafts aren't parallel anymore, this is what a double cardan (yanks call it a cv) joint is for. However if you do this then the tailshaft and pinion should be spinning on the same axis. This will mean a big diff rotation depending on the tailshaft angle.




Which means that wedges won't do it and you'll need to rotate the spring seats as Darren has done.

When I installed the divorced TC in 266 had a biiiiiiiiiiiig vibration which I traced back to out of parallel tailshafts (3.5 deg) . I had to mess about shimming the engine/trans and TC mounts and eventually got the angles to about 1 deg. Up to 2 deg is OK.

Pete
The flanges are still parallel and the tailshafts run fine and have done so for over 40,000km so far, no need for a double cardan.
As I said the engine and drivetrain is on a slightly increased slope and then I rotated the rear diff until the pinion was parallel to the handbrake drum on the transfer case, in my case 16mm worked ok but may not suit every application. From very low speeds right up to around terminal velocity of around 120+ it is smooth, no vibes.
I did have an initial vibration once the engine reached 2200 rpm which was solved by bolting the bottom torque converter cover in properly. The GM auto's are only bolted up in the top half of the circle via the actual gearbox bellhousing which allows the whole thing to flex ever so slightly. Bolting a proper cast torque converter cover in to both transmission and engine stops the flex and also stops the vibe.

Peter and Sandra James OKA 374 wrote: Pete
The flanges are still parallel and the tailshafts run fine .
As I said the engine and drivetrain is on a slightly increased slope and then I rotated the rear diff until the pinion was parallel to the handbrake drum on the transfer case,

Peter
This is exactly the way to do it. I am just cautioning against shimming up the front of the diff to reduce the angle on the unis as some sort of cure-all, as it's only part of the equation and will result in trouble if the shafts aren't parallel.
pete

Edit
and if you decide that the double cardan is the way to go then in order to get the tailshaft and pinion on the same axis then I think the amount of rotation required will be too much for wedges.
A double cardan joint is fairly long itself and you will have even less tailshaft length to play with so it gets even more important to get the angle right

I forgot to add though that looking at a lot of Oka's the front of the rear diff quite often faces downward and a long way from parallel to the transfer case which eventually causes uni failure.
I will admit though that the wedges were down as a short term fix until I could do the axle perches, just never got there )
When the Cummins goes in the angles will change yet again so I'll leave it as is until the engine swap eventuates.

And in all this messing about we have forgotten about the front diff where the pinion also needs to be parallel to the TC output shaft. You can't rotate the front diff. Even if you could rotate the front diff, it wouldn't be a good idea. A cause it would mess about the king pin angles of inclination which could cause all sorts of funny ( or not so funny) steering problems. When I did 266 I put my head in the sand on this one as we pretty much only use 4wd getting in and out of campsites.
Pete

Yes Russ, more oil to the wheel bearings, but that wasn't a priority at the time & the axle seals were in the back of my mind, but have shown no sign of leaking in 15k

I should add two things, 303 has a fairly tall rear spring set (as per previous owner) which contributed to the offset of the pinion/transfer-case. I did try paralleling the flanges via shimming with poor results as the offset was beyond the working range of the unis & still had vibration.
I also tested it with just the two unis in the shaft after we moved the saddles, as the Dana 70 is so long to the pinion, this rotated the pinion up far higher & although the flanges were grossly misaligned, the vibration was considerably reduced.
(we also mounted the engine & trans high for ground clearance)
Only then I was confident that the Double cardan joint would fix it & survive.

Pete, my front shaft is not quite perfect either, but it sounds like it is possible better than yours. Mine is acceptable for 4WD touring (at reasonable speeds), but I am about to fit my Dana 80s and new NT-Spec springs and pins and I will attempt to maximise this situation a little more.