Ford Ranger rear wheels lock while driving!

After a transmission flush, my husband’s Ford Ranger rear wheels have locked when backing out of the garage; pulling out of a parking spot; and driving down a hill.

He had checked the transmission fluid level, and it was a little high. The shop drained it down to where it should be, said the fluid was discolored, and sent him on his way. But it has happened again since then.

This is within two weeks of getting the work done. I’m afraid it will happen on a highway. Please help!

We can’t help! This sounds more like a brake problem, not a transmission problem…Was the “flush” performed by a Quick-Lube place?? Who knows what they may (or may not) have messed up…I would have a second repair shop put it up on a lift and carefully check the brake lines and linkages, especially the emergency brake parts for damage caused by improper lifting of the vehicle and incorrect operation of the shift linkage…

The problem is the rear brakes, not the transmission. However, it sounds like the transmission was not handled properly. A proper transmission flush should have left bright pink/red fluid through the transmission. None of the old transmission fluid should be left. If the fluid looks discolored. the flush was not done right.

The rear brakes locking up in reverse is a symptom of a rear brake problem with the drum brakes. The brake shoes are binding and locking into the drum. This needs to be fixed separately from the transmission issue.

This could be a transmission problem, not brakes. This is a rear wheel drive vehicle so it is possible that the transmission is locking up when in reverse or going down hill. That will certainly stop the rear wheels from turning.

And I think it is directly related to the flush, especially when the shop said he fluid was discolored. This sounds like the “mechanic” who did the job did not even come close to doing it right. This truck needs to go to a competent shop, have the pan dropped and cleaned, fluid drained, filter replaced and then maybe another flush done properly, and it needs to be doe soon before the transmission is permanently damaged.

You don’t say what year your Ranger is, but it apparently has rear wheel anti-lock brakes. Mine did. And you’ve probably never flushed the brake fluid. This leads to water and contaminants collecting in the brake fluid and jamming up the anti-lock pump. About the only repair is replacing the anti-lock pump, and it’ll probably cost more than the truck is worth. It had nothing to do with the transmission service, it had to do with neglecting the brake fluid.

If the valve-body in the transmission had debris flushed into it, it could easily be trying to engage two gears at once because of a stuck valve spool…This will lock the transmission as two gears cannot be engaged at once…The cure is to have the valve-body removed and cleaned…But we are just guessing…

I think JayWB may have hit the problem if your Ranger has rear wheel antilock brakes. I had a similar problem on a Ford Aerostar which had rear wheel antilock brakes, If I put the brakes on hard enough for the anitlock feature to work, the rear wheels would lock up. The Ford dealer couldn’t find the problem, but my independent tire store did. They cleaned a valve on the antilock brake system and that fixed the problem.

Can an improperly done flush rutpture the transmission oil cooler in the radiator?

That would ler coolant into the transmission and explain these problems.

The cooler does not get flushed…It’s bypassed during the flush operation…

Thanks, never had it flushed, just pan drop and filter change - still miss the torque converter drain plugs.