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Awd/4x4

1K views 4 replies 5 participants last post by  Mmusicman 
#1 ·
If you convert from np 136. To np233 manual shift can you in a pinch run tires not matched in diameter. Does having G-80 affect this?
 
#2 ·
If I understand this subject at all correctly:
The G-80 is looking at differential speed between the two rear axles. At some point the G-80 will engage and lock the two axles together. I have seen various statements about just when that happens, and also that above some (20MPH??) apparently it unlocks again??
Withing that narrow range, I would think the Gov-Lok would not be happy to have two different diameter tires on the rear axle. In a 'pinch' and particularly on a non-paved surface, I would not be too concerned about a short trip.
On the front, with the open diff, the wheels would think they were in a large turning radius continuously. That would definitely exaggerate wear on spider gears and its shaft but it should not be a significant issue over a short trip.
The larger the difference in tire diameters, the worse the situation gets
I would definitely attempt to have a spare that was no more than one size smaller in diameter, for anything that might require a long drive to get a proper replacement.
On a 4 wheel vehicle, replacing a single used tire that is not repairable, with a matching tire can be a challenge.
YMMV
:2:
Rod J
Issaquah, WA
 
#3 ·
Are you talking about temporary usage like a spare, or like permanently putting 2 smaller tires on the front?

As long as it's in 2WD mode then it wouldn't be a problem like it is with AWD.

Having a G-80 Mlocker wouldn't really make a difference unless it's engaged. It is a locker though, and when engaged the axles will be forced to turn at the same speed. Though with how rare engagement would be I wouldn't be too concerned with having a slightly different sized spare.

The spare I got mounted today for BB is slightly larger than the tires that are on the van(but should match once I get replacement tires), but I would just leave my transfer case in 2WD. If I still had the stock transfer case, I would pull the fuse so that it wouldn't activate.
 
#5 ·
AstroWill said:
As long as it's in 2WD mode then it wouldn't be a problem like it is with AWD..
This is correct.

As long as you stay in 2WD, you can have mismatched tires (front to rear).
You can also have mismatched tires left to right, since both differentials are open (G80 only locks after tire spin). If the G80 locks however (under mismatched conditions), I would immediately stop so it unlocks.

Running a mismatched spare is essentially no issue with open 4x4, as long as NOTHING locks up.
 
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