spinning wheel no good for xfer case?

robertf

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Jan 22, 2006
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Maybe it overheats those (fiber?) backlash takeup washers between the differential case and the spider gears, causing accelerated wear leading to increased backlash between front and rear outputs
 

WaltNYC

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Mar 3, 2010
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Does the front or rear differential not allow for the spin? I just can't understand how the resistance gets to the center diff.

(Prediction...at the end of this discussion I have an "ah ha" moment and my idiocy is revealed in full glory.)
 
Jan 3, 2005
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On Kennith's private island
The center diff of the LT230 is much like the diff in the 3rd members. The center pin is two-piece, unlike the Borg-Warner transfercase center pin. The center pin is the weak link. If the center diff is allowed to spin wildly, those pins will either come apart and jam the carrier, friction weld themselves so they no longer spin, or they'll wear to the point of failing.

If you ever have an LT230 apart for any reason, a cheap upgrade is to install a Borg-Warner center pin. It's one-piece and stronger. Or, for a little more money (~$400), you can go with a four pin center diff from Ashcroft. And while you're in there remove the hi/low lock-out solenoid.
 

robertf

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Jan 22, 2006
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If you ever have an LT230 apart for any reason, a cheap upgrade is to install a Borg-Warner center pin. It's one-piece and stronger. Or, for a little more money (~$400), you can go with a four pin center diff from Ashcroft. And while you're in there remove the hi/low lock-out solenoid.

$400? Mine was under $100
 

squirt

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Nov 13, 2008
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Los Angeles
What's the benefit of ATB over a locking center diff? Install and forget? Seems like you'd be making trade-offs vs locked setup.
 
Jan 3, 2005
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On Kennith's private island
attachment.php
 

robertf

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Jan 22, 2006
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Yeah. Those are 60 bucks. I think I paid 90 for one about 5 years ago, don't remember them ever being $400
 

p m

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Apr 19, 2004
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in this video Dave Ashcroft suggests that spinning a wheel for more than 5-10 seconds while it is UN-locked can ruin the transfer case.
I can't understand why? Can anyone explain?
The oil is flung outside of the center diff while parts of it are moving fast with respect to each other - so the crosspin or the satellite gears can get cooked.

That said... out of curiosity, I drove with rear driveshaft out, and parking brake engaged (a 2:1 overdrive in front wheel drive). Not much, only about a couple of blocks, and nothing happened to the t-case.
 

SCSL

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Apr 27, 2005
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One can pull a drive shaft, lock the transfer case, and drive hundreds of miles. The concept that this will damage the t-case is a myth within the Rover community.
 

WaltNYC

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Mar 3, 2010
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One can pull a drive shaft, lock the transfer case, and drive hundreds of miles. The concept that this will damage the t-case is a myth within the Rover community.

We are talking about an UN-locked xfer case. In a situation where the front and rear shafts spin at different speeds. In the case of a spinning wheel that difference is speed it potentially fairly high.

Back to the original point, if I understand it, we are talking about gear oil starvation inside the center diff.

I'm getting closer to 'ah ha'
 
By Analyzing parts once disassembled you can find serious wear on satellites axis, and very punished conical washers . This is always to be seen in vehicles where they do not notice to blocking by spinning wheels.
Another issue is the dynamometric brake test, with rollers for a single axis.
In times of RRs that had a viscous coupling instead of the central differential, there was a sticker indicating to avoid these tests on permanent all-wheel drive vehicles.
Wheel spin was worse for this viscous coupling than for today's central differential.

Regards
 

robertf

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Jan 22, 2006
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I just had the shop doing the emissions testing run an experiment. They roller tested it instead of two speed idle test and the result is it will in fact shit the lt230 when one half of the output is immobile. Looks like my easy no plan relaxing long weekend just got fully booked :banghead: