5.0 4R70W torque converter slamming

[FPGT24]

just picked up an explorer 5.0 and the torque converter slams when it unlocks. only does the slamming when you are cruising in overdrive and you press the gas down to get the torque converter to unlock. if you are going up a hill and the TC locks/unlocks a few times and it shifts down to 3rd gear, it feels as if the clutches are kicking when it goes back into 4th and the TC will lock up pretty harsh but it wont slam going into 4th, only when unlocking. I suppose this is torque converter shudder these trans are famous for. trans fluid looks like it needs changed, but not much of a burnt smell to it. the truck is unusually slow, ive driven a few other 5.0 exploders and this thing just seems gutless.

 

[FPGT24]

this thread section is a joke. 19 views in days.

 

[Turdle]

this thread section is a joke. 19 views in days.

Refer to the 911 sub forum rules. #3 and 4

http://www.explorerforum.com/forums/index.php?threads/explorer-911-forum-rules-must-read.143875/

However, this thread should have been moved to the stock 2nd gen sub forum sooner than now. Consider this done, as you will get more views and answers.

Thread moved to the stock 1995-2001 sub forum

edit. If driving with OD turned off, do you get the same symptoms?

 

[FPGT24]

My phone is a worthless POS so i could barely get on here let alone read the rules, I apologize. The slamming/clunk does not happen nearly as harsh when i turn O/D off, it only slams hard/clunks when TC unlocks while in overdrive, its very very bad when going up a hill, usually the TC will unlock in O/D going up hills but then ill press gas a little bit then it'll go to 3rd, then TC will lock up, and while still going up the hill it'll shift into O/D and the clutches feel like they grab and let go a few times then it shifts into O/D. the grabby feeling im describing feels about the same as driving over a set of rumble strips. ONLY does the grabby crap on hills.

I have an update - not only is the torque converter slamming as i stated above, but i took notice that the rear end is binding up and making a loud noise when i make a turn, either left or right. it also seems as if its affecting the front wheels. i got underneath and inspected everything, and the rear diff cover appears to have been off at some point. also, the front driveshaft has fluid leaking out of where it connects into the transfer case and i can see bare metal where i believe the boot should be covering it. it seems loose to me, im thinking thats the cause of the clunk/slam when torque converter disengages?

I read that the rear end binding up could be either bad clutch packs in the diff, or a bad VC in the transfer case? Can anyone else relate? I dont want to keep driving the Ex if its going to do more damage. I have a video of the noise coming from the rear end, im trying to get it uploaded.

Im not great with transmissions, so hoping someone can shed some light on this for me. Thanks for any advice in advance.

 

[FPGT24]

Bump

 

[Turdle]

If the slamming is not occuring with OD turned off, then can we assume it may be slamming when hitting 4th gear ( overdrive). The reason I suggest this is because the torque converter still locks up in the lower gears, so i would assume it would slam when overdrive is switched off if that is indeed the issue.

Let's move this again to the transmission-transfer case sub forum.

 

[CDW6212R]

If the boot is torn on the front driveshaft, it's time to rebuild that CV joint. That joint can create many odd symptoms, take care of that.

It sounds like the trans needs some maintenance, if it is savable. Unless the mileage is low, replace all of the solenoids, the accumulators(R&R the valve body), and with the VB out, install some Sonnax upgrades. Do at least the end plug o-ring kit, and the newest pressure control valve($60ish).

If that moderate work done for the trans doesn't solve the problem, then it may very soon need a full rebuild. Regards,

 

[JCat]

Please try a Google search: 4R70w Shudder

You will hear answers like:

Replace the tranny oil with Mercon 5 (only)
and
Tune it up......bad wires/plugs/coil packs .......are known to weaken the performance AND cause the shudder.

 

[FPGT24]

You gotta hit the gas pretty good when pulling out when turning cuz it feels like both the front and rear is binding up, kinda of like when you put an older 4x4 truck in 4x4 and try to turn sharp.

The trans is strong except for the torque converter shudder.

 

[FPGT24]

I'm thinking the VC is locked in the transfer case. Haven't pulled driveshaft yet to check. Hoping it's not the rear end!

 

[JK080]

Make sure the tires are all the same size and properly inflated, this can cause the transfer case to make noise.

Also may want to change the lubricant and add a shudder additive to the transfer case..

 

[FPGT24]

Tires are all the same size and tire pressure is right where it should be. How do you change the lubricant on the transfer case? I've never worked on a transfer case before.

 

[CDW6212R]

The tires being different diameters even slightly is bad for an AWD. Do a full tuneup to replace the fluids, the TC, diff's(both), trans etc.

If everything checks out after that, then temporarily pull the front drive shaft. That will stop any possible binding up of the front and rear TC outputs.

Hopefully during the maintenance, something turns up that points to the issue.

 

[FPGT24]

Does this sound like a shot rear end to anyone though? It seems like the more i drive it, the worse it gets. I will pull the front drive shaft when i have time. All 4 tires are the same brand/tire.

 

[CDW6212R]

Tire brand etc, means nothing. Only the actual diameter matters. A mix of new tires and one worn tire will kill the transfer case, which is why if one tire has a bad flat, you cannot buy just one new tire. You have to buy a full set instead of replacing one tire.

So if the tread on each tire is the same depth, then that's no issue. But if they have varying tread depths, that might be a problem.

If the rear grease hasn't been replaced in a known time, it's time to do that. Same for all fluids, don't condemn the rear by a noise only. Stop driving it and replace the fluid. If it's low or filthy, the rear may be too worn and yes needs work. But it might be simply a need for new fluid, or axle bearings etc.

That doesn't sound like an internal noise, it sounds more like an external issue, or so little grease that it's that loud outside the housing.

 

[FPGT24]

The rear cover has definitely been off recently. It has a new gasket on it. I'm starting to think that the dumbass that owned it had no idea what friction modifier is. My luck the clutch packs in the rear are shot. I'm crossing my fingers that it's just the transfer case.

 

[CDW6212R]

The factory diff clutches aren't very expensive, or strong. They can wear out in a few months given rough driving conditions. But they are not hard to change either, just a dirty job that adds maybe 30 minutes to doing the gear oil and axle bearings/seals.

I did my rear grease/bearings/seals two months ago, skipping the LS clutches. I will upgrade the diff sometime near future, so I didn't want to spend that extra time right now. I even left out the friction modifier, that's more for new clutches to keep them from chattering. Mine are likely original, and at 158k miles not very good now.

 

[FPGT24]

I'm not much of a mechanic - I can do certain things but nothing major. I spoke with one of my backyard mechanics that does work for me on and off at my car lot and he recommended replacing the rear end with one from the local you pull yard instead of messing around witht the one in it. This pull yard has rear ends for $100. I have no idea whats involved in that, he said its a ***** and that i'd have to assist - what would i be getting myself into? Any write ups on here?

 

[CDW6212R]

Lift the back end up, and check out everything, looking for anything interfering with other parts, moving parts hitting others. If nothing looks out of place, pull the differential cover. It doesn't cost much to simply change the rear end grease and R&R the cover. Inspect the gears carefully, and see if the wheels/axles turn smoothly. If you can discover any worn hard to change parts, then it might be better to swap the whole rear end. But most likely it's all usable if the grease was not bad and close to level/normal. Don't condemn the whole assembly on a guess, that's a huge job.

 

[FPGT24]

Now the rear brakes started squeaking ONLY when you turn slightly. I'm starting to wonder if these cheapass autozone lift shackes are causing some of this.