Drive shaft on backwards.... good, bad or new mod?

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DMX84

DMX84

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Sandia Park, New Mexico
I got my u-joints done at Toyota, the tech was and older gentleman & seemed real knowledgeable about cruisers.
But when I got the cruiser back and check my marks to make sure everything was kosher only to find the shaft was on backwards! :o

I'm not sure if I'd do that way, but don't think it can hurt anything.
Could this be some sort of mod to keep the slip yoke up high to prevent scraps/scratches off of the slip yoke?

Otherwise the shaft is running smooth as silk with the two new u joints.
Dean
 
I wouln't think so. It's one of those mods that would have already been done by now if it was ok. I can't think of anything bad at the moment but let me think so I can start the paranoia. :D
 
DMX84 said:
I got my u-joints done at Toyota, the tech was and older gentleman & seemed real knowledgeable about cruisers.
But when I got the cruiser back and check my marks to make sure everything was kosher only to find the shaft was on backwards! :o

I'm not sure if I'd do that way, but don't think it can hurt anything.
Could this be some sort of mod to keep the slip yoke up high to prevent scraps/scratches off of the slip yoke?

Otherwise the shaft is running smooth as silk with the two new u joints.
Dean
Click to expand...

I've seen these mounted both ways in pictures (comparing my own truck to others, etc...)

No definitive answer that I've heard of.
 
unless the splines were made to primarily turn in one direction (but I doubt that) I can't think of a reason, but this is several pay-grades above me... :frown:
 
This might help (or add to the confusion)
Prop-shaft.webp
 
uHu said:
This might help (or add to the confusion)
Click to expand...

It would be interesting to know Toyota's engineering explanation about the difference.
 
I got it up to about 75 and I think I'm feeling some vibration, it's not bad. Should I see if Toyota will have it balanced and then ask why its installed like the manual trans models?
 
beno said:
Installation of the shaft itself in terms of orientation (slip yoke xfer side or diff side) is inconsequential.

Now what does matter is if the shaft is "in phase" or "out of phase" which makes a difference.
Click to expand...

It all looks like it did before, except the slip yoke is at the t case.
I'm thinking if it was out of phase it would be a bad vibration, mine is just noticeable but I think it can probably be better.
 
why did you need to have the U-joints done? What was the problem?
 
super50 said:
why did you need to have the U-joints done? What was the problem?
Click to expand...

The rear u joint was bad - only on one axis. Meaning no slop when twisting but had 1/4 in movement side to side on one axis.
When driving it started out as a hum that developed into a real noticeable vibration.

Do you have problems you suspect might be u joints?
 
Sprung Wt.

The only difference I can think of would be that you have more un-sprung weight in the suspension system as the drive shaft is now suspended more with the axle than with the truck. I would also guess that the slip yoke is not as consistent balance wise through it's travel and may produce less felt vibration when installed at the pinion and so they do it that way normally?

I would definitely ask the tech in person and judging by his face you will know if it was deliberate or not, my guess is that technically he screwed up but who knows.
 
Are the zerks in danger of getting rocked more now than before?
 
Aldo this is an old topic it was relevant for my 60 (thanks for the answers) because the front propeller shaft is mounted backwards.
The movable part (the sleeve yoke spline) is facing the transfer and not the diff (not like FSM) but the rear is in the FSM facing the diff and not the transfer case. :hmm: it seems better protected this way?
Problem is I don't know the original alignment markings, so searching for shop: no rumbling or anything and the front is only used at limited speed (4x4 high)

Replaced U joint (landcruiser SPIDER KIT UNIVERSAL PROPELLER SHAFT UNIVERSAL JOINT)
part# 04371-36030 Stock Code 04371-36020; 04371-36021

FSM: both shaft spline facing forward:
file.php


I can state my shaft has a dent:
file.php


So if this happened because it was on backwards? maybe, don't know, dent was already there.

file.php
 
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