Things to check in transmission/drive train?

[srisitt]

I got a new-to-me manual 91 4.0L Ranger with 257k miles. What would be some good things to check/look out for in determining the shape of the transmission and drive chain?

I’ve heard one thing is if it makes a grinding sound around corners the pinion could need attention. Already found a leak in the rear diff. Anything else I should look for?

 

[rusty ol ranger]

Check the rubber shift rail plugs on the trans. Many M5ODs have croaked because of these leaking and no one checking the fluid.

Check the U joints, and carrier bearing (if equipped), all should be good and tight with no slop.

Check the diff fluid. Dont forget the front axle/transfer case if its 4wd.

In general just make sure everythings quiet, and the clutch grabs good. Not alot to go wrong with a manual.

 

[Curious Hound]

All of that plus. Check your brake system real good. Inspect pads, rotors, drums, etc. Look closely at brake hoses. If they look really cracked and old, plan on replacing them soon. They can swell up internally and act as check valves. So, when you apply the brakes, they work. But the pressure can't bleed off when you release the pedal. Then the brakes stay engaged and overheat and make you call a tow truck and cuss and swear and...... ( Don't ask how I know)

Also, if you hear grinding or roaring noise around corners, suspect wheel bearings.

Check fluid level in the clutch reservoir. Keep an eye on it to see if it drops. That is a sign of a leaky slave or master cylinder.

Get some degreaser and clean off the engine and transmission as best as you can. That will make it easier to check for leaks and pinpoint their origin.

Drive it, drive it, drive it. With the radio OFF. Listen to the whole vehicle. You are listening for bad noises. But you are also getting familiar with the sound of the vehicle so you know when something changes indicating a new problem.

 

[PetroleumJunkie412]

Grease the u joints in the driveshafts often. I use schaefers molly grease. Has been the only one with staying power; red grease and marine grease spin out for me. Every month to two in winter and once in the summer. More often if you off-road it.

I use royal purple in diffs if they call for gear lube. They seem to be loving it, but what do I know, I'm not a diff.

If a M5OD, rusty called it with the shift rail plugs. Mine are sealed in with black silicone. I run Mobil full synthetic in it and my transfer case, but YMMV.

Second on the drive it thing. Listen to everything. Inspect the weird, listen closely to the nuances to figure out if everything sounds right.

On a vehicle, your two most important safety systems are steering and brakes, and in that order. Both MUST work flawlessly. If you can't stop it, better be able to point it at something soft. Shake your steering down with an inspection and make sure everything is up to snuff. Go through the tech page on your steering.

Sway bars often get overlooked. A new set of bushings never hurt anything. Same with shocks.