Excessive Engine Movement

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Since you've isolated the problem by putting the transfer case in neutral, remove both driveshafts, and reengage the transfer case. If it binds, you know where the problem is. If it doesn't, reinstall the front driveshaft and see what happens.

As far as the rear wheel dragging, have you checked your parking brake adjustment?
 
Making progress. :) With both driveshafts removed everything was smooth -identical to when I tested with the transfer in Neutral. With the rear D/S installed there was some movement of the engine but nothing crazy and very similar to my '96 cruiser.
I then removed the rear D/S and fitted the front D/S. Selecting Reverse the first time came with loud metallic clunk. I was not able to replicate this though. However there was significant movement of the engine. Not as harsh as what I saw with both D/S installed but significantly more than just the rear D/S alone.
I am not sure what the clunk was or if it was the D/S or the diff. Either way i will leave the front D/S off and take it out for a run to see if the harsh upshifts have gone.
 
This morning I pulled the front D/S, locked the CDL and went out for a run. First selection of reverse seemed normal. Selecting D came with a lot of harshness - possibly more than I had experienced before. My drive was very short primarily because the shifts from 1-2, 2-3 were also harsh.
Got back to my garage and decided to remove the rear D/S and fit the front D/S. Again, out of my garage the first selection of Reverse was normal but selecting D was harsh. Same harshness as she goes from 1-2, 2-3. Back to the garage to scratch my head some more. When I did a final check, N to D was pretty smooth but N to R felt like the engine was about jump out of the truck.

I have checked both driveshafts and the UJ's look fine. I did have to replace one on the front but other than that everything appears to be OK. I have a spare rear D/S which I will fit and see if there is any improvement.

Both axles are non-locking and were rebuilt as part of the restoration. Any help on what I should check next is greatly appreciated.
 
landtank said:
bolts for the flex plate to torque converter loose ? just a WAG.
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I don't think so as the transmission and block was not removed from the truck during the refurb.

This afternoon I swapped in a known good rear D/S which made no difference. It's a coin toss if N-R or N-D kicks the most. What I did notice is that with the transfer in low range selecting reverse or drive feels like engine is about be launched out of the truck. Also noticed the transfer shifter gives a good jolt when selecting D or R. I checked the engine and transmission mounts again and everything is torqued to spec.
I am at a complete loss with this one. :(
 
Here is wild guess and something easy to do and check, buddies cruiser that had real hard shifts, and low range was super harsh, someone had flip flopped the tranny and cruise control cables, had the kickdown cable going to where the cruise cable should hook in the throttle body and vice versa. Routed cables correctly and shifts super smooth again
 
It seems obvious you've isolated the problem to the transfer case. I'm not sure I understand how the flexplate would have any effect When the transfer case was engaged and not when it was in neutral.
 
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ajax1 said:
Here is wild guess and something easy to do and check, buddies cruiser that had real hard shifts, and low range was super harsh, someone had flip flopped the tranny and cruise control cables, had the kickdown cable going to where the cruise cable should hook in the throttle body and vice versa. Routed cables correctly and shifts super smooth again
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I appreciate the suggestion. I have the throttle cable connected to the lower of the 3 pulleys. I am fairly sure it is correct.
 
Malleus said:
It seems obvious you've isolated the problem to the transfer case. I'm not sure I understand how the flexplate would have any effect When the transfer case was engage and not when it was in neutral.
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Are there any tests I can perform on the transfer case? I don't detect any slop when I try and turn the pinions by hand.
 
Irish Reiver said:
I appreciate the suggestion. I have the throttle cable connected to the lower of the 3 pulleys. I am fairly sure it is correct.
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should be like this

1769220218256.webp


i dont have CControl (top left slot) but throttle to the top right and kickdown beneath it
 
robnicko said:
should be like this

View attachment 4073416

i dont have CControl (top left slot) but throttle to the top right and kickdown beneath it
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Regional dialects are the best :p but I am skilled enough to translate. When I say throttle cable I actually mean TV or kickdown cable. When you say throttle cable, we say accelerator cable. Its funny but back home we use the same terminology as you do.
In any case I have my cables the same as what you posted :cheers:
 
Irish Reiver said:
Are there any tests I can perform on the transfer case? I don't detect any slop when I try and turn the pinions by hand.
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Unfortunately, I don't know of any. The gearbox is just that: a box with gears inside. They are all mounted on shafts, which are supported by bearings. Really, only three things can go wrong:
» 1. seals fail, gear oil drains out and the gears eat themselves
» 2. bearings fail and the gears eat themselves
» 3. gears fail and the gears eat themselves

If there's a bind, as in a shaft that's not parallel, in the geartrain that is the result of a failing bearing, it might show itself as a binding that resolves itself after the shaft starts turning. I've never seen this happen, but it's possible.

There might be a problem associated with the viscous coupling, but offhand I can't think of what it would be.

The transfer cases are really simple assemblies, mechanically, so it's odd that the problem isn't more obvious.

Starting from the front of the drivetrain and working back:
» You can eliminate engine–transmission mounting related probelms (I assume you've checked the bellhousing bolts), because the two are actually one unit once they're bolted together. Nothing there would "suddenly" present itself as a problem. If there was a misalignment, it would start bad and get worse, not start bad and go away.
» Nothing within the transmission manual shifting mechanism would present itself as a problem as you've described, which would resolve itself completely when the transfer case is positioned in neutral. That mechanism is just a rod and lever; you've seen it when you removed the pan. If there was a problem there, it would have been obvious.
» Removing the driveshafts isolates the transfer case from the remainder of the drivetrain. If the problem persists when the driveshafts are removed and the transfer case is engaged, but goes away when the transfer case is disengaged, the problem is in the case.
» It's unlikely, at least in my mind, that the mouting between the transmission and transfer is to blame, but that's easy to check. If all the mounting bolts are tight, the two are correctly mounted. Unless there's a crack in the case...which I would assume you'd see, or gear oil leaking would show you.

Unfortunately, this is a problem that takes eyes and that's hard to do from where I am. I wish I could be more help.
 
Thanks @Malleus for the extensive response. I truly appreciate it. It helps me align my thoughts on this issue.
I can't detect any binding in the drivetrain. With both D/S removed and the transfer in Low, i am able to spin the pinions by hand with not discernible slop. I have no leaks and i recently cleaned the bejesus out of the undercarriage so would have noticed any cracks and stuff like that.

There is definitely some slop in the front diff pinion but it doesn't strike me as much. I have more or less ruled out the actual driveshafts.

One scenario that did enter my thought process - and i don't even know if this possible- is there any way the hydraulic pressure in the transmission could be too high. It would be similar to selecting Drive or Reverse with the engine at 2000 rpm.
My idle is bang on 650rpm so not even sure if a high pressure senario is possible.
 
There is no pressure in the transmission, until the shift solenoids direct it to the shift pistons; this is what accomplishes the clutch pack compression.

Otherwise, the fluid in the case is pretty much under atmospheric pressure. Remember, there is a vent tube at the top of the case.

When you shift from Neutral to either Reverse or Drive, the shifting is done via the manual shift lever. The shift pistons only function to engage the various gear ratios above 1st gear. The ECM knows how fast you're going, so even when the floor shift lever is in "D", if you're below the 1st gear speed threshold, you're in 1st gear.
 
I'm heading over to europe for a week so when i get back i will check out the vent.
 
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