okcjeeper

Got an issue puzzling me..WHen I start the jeep I can hear and feel a rattle/clunk noise in the floor board on the drivers side. It seems to be in the rear area of the floor board by where the front of the seats mount and near the trany hump. I can hear it when I crank the jeep up and driving over rough roads and only occasionally at idle. It has me really confused, I still need to have someone start it while I sit under it and see if I can hear it then. Anyone have any ideas? It's almost like something is hitting the floor board..I am thinking maybe a bad trany mount but not sure.

jpdocdave

sounds like classic exhaust clunking near trans. i've had this on numerous jeeps, and its always the exhaust hitting the crossmember, frame, or floor.

OverlandZJ

Thats the first thing that come to mind for me as well.

Check and make sure you have the rubber bushing that comes off mount and the support arm from downpipe slides into.

okcjeeper

Now that makes sense..I hadn't eve tought about that.. I have a new cat converter, muffler and pipe sitting in the garage to install. So I'll toss that on next week when the weather clears.

I'll check all that out. Thanks you two definitely a thought I hadn't even considered..

jpdocdave

no prob, should be all it is.

oh yeah, i've had plenty of aftermarket exhaust i've put on xj's, that needed some pursuation, there's just not much room for the exhaust, new parts may still clunk. i remember a couple times the cat was too close to the crossmember, and i had to put a floor jack on the exhaust and jack up the whole jeep to bend the pipe to get enough clearance to stop the clunk.

okcjeeper

Well I will put it in and if it needs any tweaking I'll take it to an exhaust shop and have them weld it in if needs be..

90xjmark

i had this issue with mine and replaced the transmission mount and ..........problem solved

96Cherokee

where is the tranny mount?

OverlandZJ

between the transmission and the crossmember spanning between unirails.

purplexj

tranny mount is pretty simple to replace. if i can do it you can do it

96Cherokee

ok my jeep is also at fault for this noise and I know my exhuast hit cause I have no hangers left but this noise seems to be more then just exhaust

jpdocdave

almost everytime its exhaust, i've had and had to fix other's many times. and tons of times it sounds like it could be or has to be something else. the exhaust is notorious, and if you know your exhaust is hitting, fix it before you go chasing shadows. fix what you know is wrong, then move on.

bsljacques

I need to check this out...I have that same rattle at startup and idling in the morning........

okcjeeper

Yep support the tranny, unbolt the bolts on the cross member then remove cross member, then unbolt mount from tranny and reverse and it's done.

I plan on changing out the tranny mount and the exhaust system. The header and down pipe are both new so that's a non issue. I also figure the insulator cushions that the hangers attach to will get replaced as well. I'll post an update next week when I get these things done and let everyone know if that fixed it.