trans/transfer mount gone bad

[johnsonhalo]

so my truck has been making a clunking sound for a while now, and at first i just assumed it was nothing, but now it has gotten quite bad. other drivers can hear it now, which i find immensely entertaining, but i feel like having a bad mount is probably bad, so i took a look and i couldn't really see anything. just wondering if anyone has dealt with this on an old ex if anyone has any advice as to how to go about this or an estimate of how long it will take?

 

[Roadrunner777]

There is a thread on this, it's so old it doesn't show up in a search very well. Try this:

http://www.explorerforum.com/forums/showthread.php?t=56936

I'll tell you a good way to find stuff here, just use google and look for pages from this site. The google search engine is better at finding old obscure stuff.

 

[johnsonhalo]

thank you for that link it had some good info, but as far as i can tell, it's my transmission or transfer case mounts that have gone bad, not the motor. i found one thread talking about how someone had replaced theirs, but that's about all it said, didn't mention the difficulty and such

 

[Maniak]

The transmission mount is easy to change. You just need a floor jack to hold the trans/transfer case up..

The cross member the trans mount is connected to comes down pretty easy...

Make sure that is the noise though. A more common issue is a bad Radius Arm Bushing on the passenger side. Right near the Catalytic converter. When they get really bad the RA hits the RA bracket and eventually you will need to replace the bracket. That takes more time if your truck still has rivets holding the RA cross member on.

~Mark

 

[johnsonhalo]

how would i check if it's the RA? also thanks for confirming on the trans mount, i wasn't thinking it could be too involved but sometimes the simple things are the worst

 

[ppbskis]

I just had my Radius Arm Bushing and Bracket replaced last week on my 92 XLT at a cost of $ 650.00. The noise would become apparent when I would enter my usual gas station that had a slight entrance ramp at an angle. Clunk clunk, it drove me nuts, another symptom was how exciting braking and high speed turns became, you had to be a Jedi Master to safely navigate, what a pleasure since I had the work done to drive now.

 

[Roadrunner777]

I don't want to jinx this situation, but I would also like to see you writing posts next month. So, I have to ask, do you know the condition of your ball joints?

I have a similar condition, clucks on bumps. I did radius arm bushings, and it fixed some bumps and clunks, but not all. Then I tested and found bad lower ball joints. I replaced those and that helped a lot. There is some thought that a dry axle slip joint can cause this. I greased all with the prescribed dealer teflon grease, did not really help.

I now have a rare but predictable clunk. A few days ago, I heard it while I was sitting in the truck just starting the engine. So, now I know it's not running gear. I'm thinking mounts, like you are. (that's why I knew about that engine mount thread).

 

[Roadrunner777]

I don't want to jinx this situation, but I would also like to see you writing posts next month. So, I have to ask, do you know the condition of your ball joints?

I have a similar condition, clucks on bumps. I did radius arm bushings, and it fixed some bumps and clunks, but not all. Then I tested and found bad lower ball joints. I replaced those and that helped a lot. There is some thought that a dry axle slip joint can cause this. I greased all with the prescribed dealer teflon grease, did not really help. Shocks and mounts good, sway bar, all the easy stuff I checked right away.

I now have a rare but predictable clunk. A few days ago, I heard it while I was sitting in the truck just starting the engine. So, now I know it's not running gear. I'm thinking mounts, like you are.

If it were more running gear, I would start inspecting body/frame mounts, and the deeper bushings in the front dif structure.

 

[johnsonhalo]

i checked the truck today, i'll upload a pic of my RA bushings in a second, however i couldn't get them to budge no matter how hard i tried, i could wiggle the transmission just a little if i really tried, but while i was lying under the thing i realized that one of my bell housing bolts is MIA, which is definitely no good. gonna see if i can't figure out what dimensions they are so i can get that replaced

the location of the clunk seems to be about middle of the vehicle which leads me to rule out engine or front diff stuff. i read last night that if a trans mount is bad it can be hard to put in gear which is definitely a problem i have... i've spilt many a coffee slamming into second or reverse

 

[mr cribb]

#1 Does your truck vibrate going down the road? Do you feel your butt vibrate in the seat or does the dash shake?

Transmission mount.

If you have access to a vehicle lift it makes this job a hundred times easier. I did mine in 20 minutes this way. You support the trans with a pole jack, drop the cross member(18mm socket), unbolt the trans mount (19mm socket). Then install in reverse..... this is assuming you can gain access to a 4 post lift.

If your doing this in the driveway, you'll need a floor jack (mine is broke so that's why I used a lift) to support the transmission.

#2 Does your truck squeak up to 25mph in forward or reverse? Does the truck vibrate between 25-45 mph and at 55mph? U-joints.

I gave the scenarios because I just did both jobs on my truck, and this is what I felt in my truck.

 

[johnsonhalo]

it doesn't virbate to the point where i can feel it in my seat, but i can feel it in my feet, i took it to a friend who knows way more about cars than i do and he said i should check my ujoints, and sure enough the front one was completely shot. driveshaft is at a shop now getting fixed, and while there's still a bit of vibration going on no more clunk

 

[freezerlunik]

Replaced RA bushings etc., still some "clunk"/slop

Manual transmission here. I came to this thread looking for symptoms matching mine; hope I'm not hijacking asking this.

I notice the clunk/thump sound in the driveline whenever I abruptly take my foot off the gas pedal, or when I'm engaging the clutch more briskly or perhaps reversing driving direction. I do notice the shifter lever jerks maybe half an inch or so in the direction opposite and around the rotation of the driveshaft (hope that makes sense).

I have recently put in a shifter repair kit, and that took away the general slop and occasional buzz in the shifter lever. I also had my mechanic do about $700 worth of rejuvenation to the radius arms, sway bar, links and bushings. The handling is much better, no clunks gong over speedbumps even at a diagonal. If not for some steering slop due to what I believe to be tired steering gear box, it drives nearly as well as youngish minivan. Except for the slop in the driveline, that is

So now I'm suspecting that the transmission mounts may be to blame, although there is no steady vibration that would come and go at a particular speed. Mechanic was pretty adamant that the mounts are okay. I am also thinking perhaps my rear differential needs servicing and there are worn out clutch packs or spider gears? Bought the car in June, have no prev. service records.

 

[Anime]

I notice the clunk/thump sound in the driveline whenever I abruptly take my foot off the gas pedal

The clunk/thump is the flywheel/transmission suddenly slowing down along with the engine when it's all connected under load/acceleration but you suddenly let off the gas.

The solution is to not abruptly take your foot off the gas pedal. Sometimes it will clunk anyway though, and it's unavoidable, like when accelerating going uphill but then letting off the gas just a bit to maintain speed rather than keep accelerating. It's also something that gets more pronounced with age, so a newer manual with less miles or a completely rebuilt one won't clunk near as bad as one with hundreds of thousands of miles.

 

[freezerlunik]

Alright, counting that as a vote for the transmission generally being worn out, causing the slop. I have an extremely slow leak somewhere at the top-rear of the bell housing, and had it cleaned in and effort to pinpoint the source.

At the same time, this guy seems to make a convincing case in favour a worn out differential being the cause of a thump/knock/slop:


I think I'm up for a visit to a specialized tranny/differential shop nearby.

 

[Anime]

Leaks at the top of the bellhousing are usually from the engine, either a valve cover gasket, or head gasket. Valve cover gasket leaks are fairly common, head gaskets don't usually leak unless the engine has overheated.

Worn out clutch parts from a limited slip trac-loc differential could cause noises, but an open diff won't "wear out" unless the gear oil is neglected.

The driveline has a lot of potential points that cause looseness and clunks, from the u-joints, to the slip joints, the pinions, and even just the yokes. Overall, you need new u-joints, re-greased slip joint splines, and torqued yokes to be sure the clunk is all in the transmission. Even then, with a perfect system, the manual trans in an Explorer will clunk when you suddenly let off the gas with the drivetrain under load. There's nothing that will make it go away, other than not suddenly letting off the gas.

 

[freezerlunik]

Thanks, Anime! I live in a part of town with steep hills, and plenty of traffic lights that make occasional enthusiastic shifting and launching uphill a requirement.

I'd happily live with the symptoms had I at least an e-brake with a handle at my disposal. For now, this loose travel between what the engine is doing and what the rest of the car is doing is the 2nd biggest issue with my otherwise well-behaved truck.

I did some leisure driving tonight, and find that the shifter+transmission have a noticeably wider amplitude of bounce when I drop the gas while in lower 3 gears. I compared while travelling on level road, with engine at 2500-3000rpm before I released the gas.

Doing a mental experiment based on these observations, it seems that if my issue is mostly due to parts beyond the transmission, then the amount of free travel felt when dropping the gas should not depend on what gear is engaged. So I'm going with the "slack in transmission" as the main culprit, but will probably do a differential service as a first step, just because I never even cracked it open and it's likely much cheaper than freshening up the M5OD will run.

 

[mr cribb]

By not shifting at 2500-3000 rpm and doing so more at 18-2200 rpm's the trans doesn't clunk near as bad.

 

[Anime]

Changing the fluid in the trans with new DEX/MERC ATF can be a good idea too. Old, thin fluid causes wear and lots of other issues. Fresh ATF makes for a quieter trans and usually smoother shifting.

 

[freezerlunik]

Thanks for all the comments, guys! So I did the mount (went with energy suspension parts one) about a month ago, and it definitely helped some with the amount of play I was seeing with the old mount.

The instructions that came with the mount also advised to always change the front engine mounts together with the transmission mount. So I'm not sure if it's just an up-sell strategy or a genuinely good advice.

Overall I think I won't be happy until I get a newish tranny in there or do a proactive overhaul to mine. It just drives me nuts having the play in the driveline, kills a significant chunk of the joy of driving a stick!