Hello all, I'm new to the forum but I've owned a 1989 Ranger for a long time... I have a driveline vibe issue that has me stumped. The truck is a 2.3L with the M5od transmission and 4wd. It has 176,000 miles on it. For about the past 6 months, I have had vibrations that feel like they come through the floorboards or from the rear end. They started soon after I changed the transmission fluid but I didn't think they were related. I put Mercon ATF in it. The vibrations only happen between about 25 and 50 mph, and they seem to change in intensity going around turns. They can happen either under load or coasting. It's kind of like a low growl or rumble. Because of how it changed with turning, I thought it might be differential bearings -- replaced the carrier bearings and outer axle bearings on the rear end, and that didn't change anything. Also replaced the u-joints in the rear axle. Front wheel bearings were replaced a year or so ago, but the problem definitely seems to come from the rear. So I'm thinking transmission, but I don't know what could have happend or why changing fluid made it get so loud. Has anyone ever had something similar, or any suggestions?

Thanks

 

does it do it when you push the clutch in or put it in neutral. i have the same truck in a 99 and mercon is recommended for my truck. tires out of balance?, air in the power steering? does the 4wd have a yoke in the driveshaft. I think they ned synthetic lube?

 

Yeah, when the clutch is in or it's in neutral it will still do it, as long as it's between about 25-50 mph. I got the tires balanced as well, forgot to mention that, but it didn't help. And my 4wd doesn't have a yoke in the driveshaft. The steering acts odd sometimes though, like the power steering goes in and out. How would I know if there's air in it? Is there a bleeder valve or something?

 

You may have more than one problem.

Do you have a two piece rear drive shaft????

On the power steering boost coming & going, is the fluid low????

Whats the P/S fluids condition, has the system ever had a flush & complete fluid change????

 

if you think you need to bleed the PS there is a lot of info around here on how to do it. you could try the lazy mans way. go to a parking lot and slowly drive in figure 8's. that sometimes works. has your fluid run low. sometimes the fluid leaks into the bellows( if you have them) and you cant see any leaks until the bellows break. as i mentioned earlier some of the newer trucks have a real short second drivshaft that needs grease. i guess you dont have that. the recomended fluid is mercon/atf

 

The rear drive shaft is in two pieces, with a rubber boot hose clamped over the area where they come together. There has always been some slop in the connection, but I haven't noticed any more than usual. Is any play in that joint normal? There aren't any grease fittings around it.

Occasionally I have to add a little P/S fluid, but it never gets so low that air could get in the system. I have never flushed the fluid though, and it's pretty black.

 

that joint might be your issue . there are threads around showing how to grease it properly i think they recommend synthetic grease. do a search. i think it is called a yoke

 

paw paw would know this better then I.but as i think about it if it does not change when it is in neutral I wonder if that is the issue. I would think when there was not a load on it that it would change some? see what paw paw says

 

There is a TSB out for cleaning & lubing the two piece driveshaft splines with a teflon loaded grease & there is an article in the "Tech Info" thread atop this forum on the two piece driveshaft.

Could also be some other things as well, so maybe look through this thread for other ideas & see which one seems to fit your symptoms & let us know what you find.
https://www.ford-trucks.com/forums/7...aul-ideas.html

More thougths for consideration.

EDIT: WOOPS, forgot about the P/S question, your fluid sounds like it's past needing a change, so maybe a cleaning of the system with Seafoam Trans Tune & a flush with new fluid is in order, anyway here is what I've done to fix my shuddering P/S systems on the 94 Taurus & 99 Ranger.
https://www.ford-trucks.com/forums/7...ml#post7708992

 

Sounds like the yoke in the rear axle might be a problem. I've noticed that the connection there is kind of sloppy before but I never gave it a second thought. I will check that out this week and see what I find. As for the P/S, the cleaning and flush is probably a good idea. For the five years I've owned the truck it has always spit fluid out when you turn the wheel the whole way at low speed, and it seems like I only get P/S boost intermittently at times.

 

Sorry it took so long to get back to you guys, I have been busy.

I lubed the spline where the pieces of the driveshaft meet. It seemed to help the vibes a little bit, but they are not completely gone. Still vibrating at 35-45 mph, and intensity changes sometimes after going around turns. Vibrates in neutral the same as it does in gear. As a recap, I have replaced driveshaft U-joints, lubed the spline in the driveshaft, replaced rear axle carrier bearings. I am at a loss. Should I try to get the shaft balanced? The only other bearings are pinion bearings at the rear axle or the transfer case, but I don't want to get into that unless I know they are bad. Also a friend mentioned that if any transmission, engine, or spring mounts are bad, they could cause those types of vibes, but I could not find anything loose on any of the mounts.

Any new ideas?

 

The biggest clue I saw was that in vibrates the same in Neutral as when i n gear. that eliminates a lot of stuff. does it vibrate at idle or are you talking about when you are driving you put it in neutral and coast and the vibration is still there

 

No vibes at idle... it vibrates whether you are coasting or accelerating when the truck is moving between 35-45 mph...including in neutral. So it is vehicle speed related, not engine speed related.

 

I've had a vibe in my 97 ranger for a while now. Have done all the usual, U joints, hanger, balance tires, even changed rims and tires. Turns out it's in the rear end. Almost feels like I have a flat when I'm goin down the road now. I've been told it's either an axle bearin or pinion. I've never worked on either so it'll be a learning experience. Maybe that's your problem too. Justa thought

 

Have both of you tried swapping both rear tires, one at a time, back to front, to see if the rear vibration stops????

if so, have you had your tires "wheel force" balanced????