Rear Wheel-spin While Driving On Wet Roads

[Dubious_Downfall]

Picked up my 1992 Mazda Navajo LX today. Automatic transmission. She's got the D4 axle code, so 3.73 limited-slip front and rear differentials. 4x4, but the button assembly is missing, so I haven't checked if the old auto hubs lock up yet.

So, I live in Washington. It rains. A lot. It was raining steadily all day today while I was picking up the Navajo. I noticed on the drive to the parts store that when on flat road or uphill inclines, it sounds like one of the rear tires spins if I gas it, at all. On the steep incline, I could barely speed up. If I tried, I'd hear wheel-spin and get a slow speed increase. I've driven my Explorer up this hill a hundred times. It's never had a problem picking up speed due to wheel-spin, but it's a 41 axle code, so open diffs, fairly low gearing, can't quite remember the exact number.

The last time I drove a rear-wheel drive vehicle with a limited slip diff was over 9 years ago, before I even had my license. So, I can't tell if this is something that's normal on a rainy day. It seems absurd for it to be normal, frankly.

I'm going to be throwing my Explorer wheels and tires on it, so I'll find out if two mismatched rear tires could cause the issue. I'm also curious if a rear brake problem could cause the wheel-spin. The rear anti-lock brake light is on and the pedal is squishy. Bleeding the system tomorrow.

A rear diff fluid and clutch pack change are on my short-list of maintenance, so I'll find out if that makes a difference. Watching that ChrisFix carbon fiber clutch-pack video will finally come in handy! Also going to check that the diff breather tubes are working properly.

Sorry for long posts. Lol. Thank you for any input.

 

[Masterd]

My Ex cuts loose on rainy days too. Mines an open diff and it'll ride the painted line sideways if not careful.

If yours is actually a limited slip I'd get in there and rebuild it, or make sure it wasn't swapped for an open unit.

 

[974X4BLACKSPORT]

If you have anything other then both wheels spinning on your LSD, you no longer have LSD. I sounds to me like you have bald rear tires, and a very worn out LSD, probably from some one using mis-matched size tires.

 

[Albino 94LTD]

Consider yourself lucky to have enough power to spin the tire(s)

The items on you maintenance list should help.

Good luck

 

[CDW6212R]

Ditto, the tires are worse than your Explorer has, but the LSD is worn out too.

Be careful with both tires able to spin, it's easy to get the back end sideways if the road isn't dead even(not slanted to the side). Turning a corner with an LSD in the rain can surprise you if you use too much gas.

 

[RangerX]

Just a note, D4 means 373 with LS in rear only, not front and back. No gen1 ever came with a front LS.

 

[CDW6212R]

.... No (Explorer) ever came with a front LS.

 

[Dubious_Downfall]

Just a note, D4 means 373 with LS in rear only, not front and back. No gen1 ever came with a front LS.

Fair enough. Thanks for the correction.

 

[Mbrooks420]

How are your tires? Even open diff it shouldn’t be super easy to spin the rears.

On dry pavement both rear wheels of a LS most likely won’t spin. The spec on the LS breakaway is only 20-30 ft pounds. They spin at different speeds all the time.

 

[Dubious_Downfall]

How are your tires? Even open diff it shouldn’t be super easy to spin the rears.

On dry pavement both rear wheels of a LS most likely won’t spin. The spec on the LS breakaway is only 20-30 ft pounds. They spin at different speeds all the time.

The tires look alright visually, and are the same size, but different tread styles. I'll air up the tires after work. I actually found out yesterday that the tire spins basically just as easily on dry road.

I'm confused, but I have to keep driving it. I'll report any news.

 

[CDW6212R]

Hard rubber tires, time to replace them.

 

[Mbrooks420]

If they are different treads they are very unlikely to be the same size. If the tires are spinning, and it’s not the transmission slipping, I agree with above that it’s time to replace all 4 tires with matching size and tread.

 

[Dubious_Downfall]

I just thought I'd make an update, despite not really having anything to show for the time.

I have all of the parts, tools, and fluids required to replace the friction pads in my rear differential. I may have also finally found a place that will let me get that work done.

My tires, on the other hand, have been given no attention at all. I just drive it with the slip in the rear. Probably to the detrement of my axle and rear bearrings. I will be making tires a priority as soon as I have an at least semi-permanent place to live.

I will let you guys know how the rear diff pad replacement goes. If anyone is curious, or attempting the same repair, I'll be following the video ChrisFix made when he did the same repair, but with carbon fiber clutch pads, and on his Mustang. Either way, it's the same old Ford 8.8".

The next thing I'm doing, before anything else, is front and rear brakes. I have everything needed. My front left brake hose is leaking, and has been since I got the old girl. And my brake pads, rotors, drums, and shoes are all each on their last legs. Every brake part attached to the wheels is getting replaced, including the calipers and wheel cylinders.

This truck has really showed me some love, and I intend to show some right back. I drove it for two months solid with the water pump and radiator both leaking like crazy. I had to put over a gallon of water in both before and after work. But the Navajo never even flinched. It got hot, but never lost pressure or died on me. I don't deserve this truck. Not for the $350 I paid for it. So I'm going to keep her purring as long as I can. Because this truck is one tough SOB.