[cooper30]

1990 4x4 RC 318/A518/NP241

When I put the truck in gear, I get a small vibration/shudder. This happens whether I go from P to R or D and also from N to D or R. The truck does this little vibration while standing still, foot on the brake.

While driving, the vibration/shudder is really noticeable in 2nd gear. As soon as the tranny shifts from 1st to 2nd, I can feel it.

The kickdown linkage has been adjusted as per the fsm. The bands were adjusted about 200 miles ago. Today I checked out all the motor and tranny mounts. They are solid. I also removed the cover and checked out all 4 of the flex plate/torque converter bolts. They were all tight. I also saw no problems with the flex plate itself. From what I could see, the places on the torque converter where the bolts thread into were all solid, too.

As a side note, the front end on this truck is new...ball joints, tie rod ends, etc. The front tires need to be balanced, but I can feel that problem through the steering wheel. Besides, unbalanced tires will have no bearing when the truck is standing still.

I am having no problems with the tranny such as slipping or anything like that. Oh yea, fluid level is correct, too.

Any thoughts?

Thanks,
Ted

edit: I just went out to look at the damper. It seems ok, but how exactly does one check the damper?

 

[SeahawkDodge]

How much play do you have on the rear driveshaft? Where is the play, on the tcase, the u joints or the rear end?

 

[cooper30]

How much play do you have on the rear driveshaft? Where is the play, on the tcase, the u joints or the rear end?

U-joints are new. Less than 100 miles on them.

The play is in the transfer case. However, the 208 I pulled out of my 84 has a lot of play and I didn't have any problems like this.

I just had the driveshaft off to do the u-joints and put a different rear axle on (from my 84), that's when I checked the play. I had this problem with the original rear axle, though.

Thanks!!

Ted

 

[Knaranek]

I have seen drive shafts do just that in Ram trucks. Check the balance on your driveshaft as well.

Hope that helps!!!
Jim

 

[SeahawkDodge]

How much play do you have on the rear driveshaft? Where is the play, on the tcase, the u joints or the rear end?

U-joints are new. Less than 100 miles on them.

The play is in the transfer case. However, the 208 I pulled out of my 84 has a lot of play and I didn't have any problems like this.

I just had the driveshaft off to do the u-joints and put a different rear axle on (from my 84), that's when I checked the play. I had this problem with the original rear axle, though.

Thanks!!

Ted

I don't know then. Maybe something internal on your tranny or tcase is slipping (thinking tranny more likely)... Sorry I can't help more Coop.

 

[chrysler300le]

I think its time to do a tune up. The problem is with your engine. When you put it in gear your bogging the engine down and thats why you get a vibration while in gear with foot on brake.

 

[Bummo]

Ya, that could be. Cant be driveshaft or anything rotational if its vibrating while stopped. How about torque converter?

 

[chrysler300le]

Nope, its got to be in the engine.

 

[cooper30]

Well, after 2 days of chasing the vibration(s), it's much better.

Problem is, I did so much that I'm not sure exactly what fixed it.

300le, I followed your lead. Since I did a basic tune-up about 300 miles ago, I went back over everything that would cause a vibration with the engine. I loosened and then retorqued all the mounts, and checked everything I could see or think of. I'll need to get motor mounts eventually cause the rubber is in bad shape. I even checked the tranny to engine bolts (bell housing). Hell, I even made sure the axle u-bolts were tight.

I took all the tranny cooler lines off and flushed them and the coolers, too.

I took the driveshaft off and made sure I did the u-joints right, then I put it in 180* off. I also took the slip-joint out, cleaned all the crap off the splines, and then drilled it for a grease fitting. Clunk's gone, now.

Basically, I went over every area of the truck, following the chapters in the fsm. I found a lot of things I want to replace, but no major problems.

I went on a 100 mile ride this afternoon, and it definitely rode better. Still vibrates a little, but nowhere near as bad as before. lol, I even got 11mpg (the original window sticker says 11 city/13 highway)

After all that, I have learned more about my RC than I ever thought possible. Too bad I saw all kinds of things I want to spend money on now.

Thanks for the help!!!!

Ted

 

[chrysler300le]

Its possible one of the plugs that was replaced went bad or a bad wire. A vibration while ideling in gear tells me the idle mixture or timing is way off or its not running on all cylinders completely. Pulling the plugs out could show maybe a difference in plug coloration. Since you did take it out for a trip and put some miles on it. Could it of been bad gas you had before? Did you fill up before your trip?

 

[cooper30]

That's good advice that I'm going to take. Thanks.

I did fill up before I left. I'll pull the plugs and see what they look like. I never thought of that.

Thanks again,
Ted

 

[ddman]

well i have been chasing a vib. myself for sometime. and the guys on here told me several things to check. well i did it all turned out ok and still had a vib. i had checked my fan clutch and it didnt feel bad to me at first but after rverything else i took it off and started the truck and it didnt vib at all. but i also didnt drive it. my problem was in the take off, right as you start to move i t would shimmy, i did everything changed ujoints, axle bearings, plugs and wires, checkedthe yokes mounts you nameit i done it. hopefully this is it the fan. the truck didnt seem to vibrate setting there at idle, but when i pulled off the fan and started it, i noticed the difference right a way. this may help you. i am going to put on a solid fan and give her a drive. but have my finger crossed.

 

[Smokey]

I was thinking of accessory brackets and fan too. It sounds like it's a resonant frequemcy that vibrates at low rpm (take off and just after shift) but not elsewhere. In your tightening spree, did you check all the alternator, PS, air pump, whatever, accesory brackets for tight and belt alignment?

Do the standing still check with the hood open and look for the alternator to be shaking back and forth, or...

And, as ddman says, could be, could be...