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View Full Version : 5th Gear Vibration?????? 97 Cobra


ffcobra
07-04-2005, 12:34 AM
I noticed today coming home from work i get a 5 gear vibration but, only sometimes. If i take it out of 5 it goes away and if i push the clutch in and rev on it it goes away. I'm stumped. It comes and goes when it wants mainly accelerating around 60 and if i let off the gas. Its not like a real bad shaking but it is definalty noticable anyone have any clues.Thanks in advance.travis

JBoden
07-04-2005, 08:14 AM
First thing I'd suspect would be u-joints. Be sure to carefully inspect them, if you see any "looseness" - get them out of there, they tend to get worse really quickly.

If the u-joints and drive shaft appear OK - the clutch would be my next thought. Are you still running the original clutch, how many miles on it ? Blowers put alot of extra HP thru the drivetrain.

Bartman01
07-04-2005, 01:24 PM
Get your tires balanced/rotated at a good shop and see if that changes anything. It's probably not a tire issue, but if it is you can spend a lot of time looking for it elsewhere.

ffcobra
07-05-2005, 01:27 AM
thanks guys. I dont know why i didnt think of u joints.Would the u joints be bad in all gears or particularly the higher up? I'm not being a smart @ss i really dont know lol.And i got bnew tires all the way around less than 5 months ago. hmmmmmm. i did crawl under ther etonight to change my oil and grabbed the drive shaft and turned it it has some play but what is excessive. thanks guys travis.

oh ya its a spec stage 2 clutch with the metal throwout bearing not that plastic stuff. thanks

rpalmer
07-05-2005, 06:44 AM
U-joints would likely be a speed dependant vibration. The vibration would be at a certain speed, regardless of gear.

But I'd get under there and see if you can detect any looseness.

-RP

ffcobra
07-07-2005, 01:21 AM
o.k i crawled under there today after i got off shift and, it seems that my rear end has been leaking and possibly empty. You think that could be the reason. I dont think its all the way empty but its definatly low. So i guess i will be doing that tommorrow. I hope this is the problem because i have long tubes and there aint nothing fun about those. Thanks again guys. travis

JBoden
07-07-2005, 08:56 PM
Differentials are pretty foregiving but if you've been running really low on gear lube it could hurt the diff and this will be expensive. Try to measure how much you actually have to add before beginning to worry. I assume it's the pinon seal that's leaking, definately fix the leak.

The rear-end holds approximately 3 quarts - if you need to add 2 qts to bring it to the fill hole - I'd consider pulling the cover and visually inspecting the gears.

You'd typically hear the gears "whining" if there was a problem but many of us have such loud exhaust, stange noises can't be heard.

Good Luck :thumbsup:

ffcobra
07-08-2005, 09:25 AM
thanks for the input guys. I found it wohoooooo. I feel so stupid i shouldnt even post. I did go ahead and take the cover off and replaced all the lube.And just my luck it was full lol. The driveshaft bolts where loose. What a moroon. I thanks you guys for all your help. I gues if you see more post by me slap me in the head and tell me to check simple things first.Travis

JBoden
07-08-2005, 08:42 PM
Glad you found the problem :D

Loose drive shaft bolts are unusual - unless the drive shaft has been removed for a gear change and the bolts weren't torqued properly and with thread sealant (Loctite).

Keep an eye on this - it could happen again.