i i i c c cant drive 55 (in fourth)

[kayoteq]

What complicated thing is causing the car to vibrate like a misaligned tire at 53-55 but goes away if clutch or third gear.. is engaged.. or faster or slower.

 

 

Initially was blaming this on me and laggy shifting but at this point

it seems fairly consistent. Usually work up speed in third downhill to get speed to be over 55 in fourth.. when conditions permit.

 

 

 

No obvious noises the key of most other clutch /tranny issues.. no grinding,

Alright I can hear something when the car is out of gear that goes away if i clutch..

but more of a rumble than a rattle.

 

thinking if getting that valvoline synthetic gear oil and give it a change. Probably the easiest way

for now.. long term I plan to five speed it but not. Right. Now.

nothing amiss other than perhaps a disabled hill holder, but that would not seem relevant..

 

 

Perhaps previous owner went 55 just a bit too often?

[Fairtax4me]

4wd or 2wd? If 4wd could be a U-joint. Could be the carrier bearing on the driveshaft.

A bad cv axle could cause this. Wheel bearing, ball joint or tie rod end maybe.

[ShawnW]

Lots of ways to narrow it down. You mentioned 4 speed and this is the 80's forum so I assume EA81 body car.

 

I start with tires usually. Rotate front to rear. Old tires, or old steel "wagon" wheels both are known for being culprits in the vibration battle at times. The Alloy wheels can be a little hard for some shops to balance-the wagon wheels are often bent.

I have seen people running the wrong lug nuts and such with strange vibrations.

Driveshaft-mentioned-very common for a u joint to get dry on these. Check to see if they have grease zerks on them. If they do-grease and road test along with inspect them for play of course. If you have a spare driveshaft thats easy to swap out with 4 bolts.

 

I assume you have tried going past 55 and taking it out of gear to see if it really does vibrate only at that exact speed.

[kayoteq]

Sorry forgot.. 85 brat

levels and alignment are good..

vibrations

Show up at 50-55 then dissapates at faster or the usual slower.

only with 4th engaged. 3rd or clutch coast in no rumble.

Gears are otherwise fine..

[Yo'J]

I have a 5speed dr in my brat that has a strange vibration only in fourth gear at 60mph. I think its a worn gear. It only does it at 3500 rpm and up and only in fourth. Fifth is smooth all the way. Does this sound like your prob?

[kayoteq]

I've not distinguished between cold and hot conditions regarding the vibration..

but at the moment may go for the fresh fluids and see..

Yeah right in the 4th only no fifth for me despite my early attcrrrrrempts.

 

So.. worn gear? Better change fluid anyway to check for gear bits.

I bet its not as simple as "bench trans remove access panel remove 4th replace"

(Not that there's ever been one that simple..)

 

_------update------

Btw no other problem went up to 3200 ft from 1100ft elev. in six miles.. appy mountains.

 

Okay how about this..

thinking about the mechanisms and how I'm coming in from a habit of shifting Volkswagen..

 

So.. third-clutch-neutral-release-clutch-select gear and smoothly engage 4th.. seems a bit more in gear?

Importantly no apparent vibration.

 

So.. bad technique clutching or x component..

or learn this method and have happy 55s.

Edited May 10, 2012 by kayoteq
double clutchin it