I have a 1993 pickup, when I hit speeds over 40 mph my rear end starts making a grinding noise off and on. Could this be a bearing.

I have access to a 89 6 cyl pickup, mine is a 4 cyl. Are the rear ends interchangable.

 

Check your rear drive shaft u joints.

 

Deff check the u-joints. Get under the truck and try to wiggle them. If they're all good the next thing i would check is the oil. If theres a fair amount of metal shavings & bits it could be a chipped gear. Otherwise it could be a bearing. Not sure off the top of my head how to check a bearing aside from actually pulling it, which is why i recommend the other checks first.

not sure about interchangablilty, but i know the gears are different.

 

Not sure if your year of Toyota has a magnetic drain plug in the rear differential.

But drain the oil and have a look. If there is a Ton of metal sticking to the magnet, you may have internal problems.

 

Ok I have to ask, If your rear end is making noises have you been eating south of the border?



Seriously though
From my 1988 truck FSM the causes of noise in rear axle are.

Oil level low or wrong grade
Excessive backlash between pinion and ring or side gear
Ring, pinion or side gears worn or chipped
Pinion shaft bearing worn
Axle shaft bearing worn
Differential bearing loose or worn.

Im not positive, but if I think you could swap the 3rd between the two trucks. The internals of the third are different between the v-6 and 4 cyl, but from what I have been told or heard that you can swap out the whole third assy with no problems. You just cant put in a v-6 ring gear into a 4cyl carrier or vise versa. Only thing you would need to check first is to see what the gear ratios are, if they are the same I would try to swap them.

 

The third members, or entire rear axles are totally interchangeable, provided the r&p gears match. You can do a ring & pinion swap from a V6 to a 4cyl third member with no complications. The opposite, 4cyl to V6, requires a spacer to make up the difference in the inner pinion bearings. Due to the difference in driveshafts the flanges, where they bolt up, you'll need to change, but they can be swapped to make whichever work on whatever. Or, you can drill new bolt holes in the flanges for the different driveshaft bolt pattern.

It would be an upgrade to go with the V6 3rd, even with the 4cyl r&p which isn't really "better" in the V6. It's the actaully carrier that's redesigned to prevent side gear failure, which is the weak link in the 4cyl 3rd. They also put a larger bearing on the inner pinion to strengthen that area due to the potential extra stress put on it buy the tougher differential gear assembly or upgrades like lockers. As well, the third member case itself is stronger/heavier, thicker metal.

 

disregard, didnt mean to post here