Is it my transmission??

[arnoldv]

1991 Navajo 111,000 4.0 V6

When going 55-65mph and then shift to Overdrive, while accelerating, my car shakes a lot. And when shifting from Overdrive to Drive at high speeds, my car shakes once.

What the hell is wrong????

 

[arnoldv]

And when I'm reversing, it shakes a lot, too. Kinda like Overdrive.

 

[ajevenson]

A U-joint maybe? Do you hear a clunking noise when you intially put the vehicle in drive (assuming its an automatic)? Or if its a standard does it clunk within 50ft of driving once the clutch is released and you are starting to accelerate? Those are indicators that the u-joint is toast.

 

[arnoldv]

It only happens at freeway speeds. It's an automatic.

 

[ajevenson]

Check your tires to make sure they are at the same pressure. It could be your alignment as well as a tire out of balance or round (have you hit anything big recently?).

My truck shimmies and vibrates when I hit 105kmh (65mph). This is because I have replaced the front tie rod ends and not yet gotten an alignment. You wouldn't think I need one because the truck drives perfectly straight. It only shows the effects at high speeds.

 

[arnoldv]

Originally posted by ajevenson
Check your tires to make sure they are at the same pressure. It could be your alignment as well as a tire out of balance or round (have you hit anything big recently?).

My truck shimmies and vibrates when I hit 105kmh (65mph). This is because I have replaced the front tie rod ends and not yet gotten an alignment. You wouldn't think I need one because the truck drives perfectly straight. It only shows the effects at high speeds.

The funny thing is this never happened before I brought it to a shop for a tune-up. Those f!@kers must have done something to it.

 

[rjc]

I had an old 68 ford Galaxie that developed U-Joint problems about 170,000mi. This was about 92 or 93 when. When I pulled the drive shaft the bearings were powder and the car would vibrate down the road and clunk when put in forward or reverse. For you sake I hope it's not the tranny. I spent about $20 or so for grease fitting type fittings and did not have any trouble installing them with a hammer, some sockets and a vise. You use the vise and socket to press the end caps of the new U Joint in place. You don't want to bang on them or over compress them. Just get them in so the spring clip retainers can go on the ends. Make sure you paint a mark on the shaft so it goes back the same way as it was originally balanced. About the same time I also had to replace the rear wheel bearings which if the same in the explorer are sealed for life bearings that are not lubricated by the rear axle oil as you would think. They are pressed on the end of the axle. If you hear sqeeking they may be intermittently locking up and are spinning on the axle like mine were on my 68... not a good thing. They came off with 10,000 pounds pressure and the guy at the machine shop said they went back on with about 6,000 pounds. Just something else to consider if it's not the tranny. I don't think the rear wheel drive components have changed much over the last 30 years. rc

 

[UBBA]

This is going to sound crazy but I had the infamous shakes on my 92 eddie B. , I changed radius arm bushings, tires, shocks, wheel bearings, u-joints and guess what.. my tranny fluid was too low causing the shake. I went ahead and changed fluid and filter and the shake got way better but since I got 120,000 on it im looking for the tranny to go before long. Good Luck.