Tracking down Shudder with a upgraded pump and new Hemi TC

Mountainman · **Posted:** Wed May 18, 2016 10:48 pm

First off, can adding more fluid help with shudder? I've added about 11-12 quarts after a complete drain. The shudder is worse when cold, I think.

EDIT: After the TC is locked it all of the sudden disappears, so it's almost certainly the TC causing the shudder?

Here's where it gets complicated. I also swapped the transmission for a much lower mileage one, 108k miles to be exact. It has the new pump. Pretty unimpressed if I got a faulty new Hemi TC.

The 108k transmission was well maintained, but am I correct in thinking that several other parts in an auto could cause shudder around the same point that our stock TC's shudder? It is definitely right in the same place as I got shudder with a stock TC. It started as a light vibration, but today it felt a lot worse, still not as bad as a stock one, but worse? this isn't good :banghead:

Hopefully more fluid and or some Dr shudder or whatever it's called will fix this? I really don't want to overfill it though.

Another EDIT: I does look like a completely empty one should take closer to 13-14 quarts? Maybe I just need more fluid. If I go really slow to the first shift, it has a strangely solid shift that feels almost like it's throwing the jeep forward a bit, but I've felt that with my old transmission as well, and it also had the upgraded pump...

Thanks for any wisdom on this :ALONE:

ebbnflow · **Posted:** Wed May 18, 2016 11:36 pm

Did you do a quick learn on the TCM after you replaced the transmission and TC?

flash7210 · **Posted:** Thu May 19, 2016 7:58 am

Lets see if I can follow this...

You have a new 545rfe
a new transmission pump
a new Hemi TC
and you are getting some shudder

At what speeds are you noticing shudder?
What engine tune are you using?

By all means, add some Dr Tranny Shudder Fix and a little more ATF+4. It cant hurt.
But you say that you get some shudder but then it stops and holds.
This kinda makes sense if the TCM needs some time to learn the new transmission.
Also, if the TC was bad, you wouldn't be able to accelerate (from 50+ mph) without severe shudder.

It could also be a line pressure problem, in which either:
a. you need to give the TCM more time to learn, or
b. you have a faulty pressure sensor, or
c. you need a line pressure booster

If nothing else works I can send you my Sonnax pressure booster to test and see if that helps. I havent installed it yet.

Mountainman · **Posted:** Thu May 19, 2016 11:16 am

ebbnflow wrote:

Did you do a quick learn on the TCM after you replaced the transmission and TC?

I forget what a quick learn is, but I just did the "drive around town, with lots of stop and go" the first day, and then rural highway, and offroad with a lot of time in 2, so it wouldn't shift constantly between 2 & 3. Spent time bashing through snow drifts, got stuck, jeep about slid off the road, had to tie it off to a tree, sorry, though you guys might get a kick out of that.

um, I also swapped in a GDE eco tune TCM. The engine tune is an ECO also.

Yes on the new transmission (well, it has 108k miles on it), and the new pump was probably installed about 50k ago.
Yes on the new Hemi TC. I got the OEM one just to be safe, or so I thought. There were cheaper options.

Ok, I'll go read up on the quick learn, and from what I think WWdiesel wrote in a thread, he said to go 1/2" about the full mark, so I'll try that. I know my old transmission would leak out the extra when I added a little too much, and then it quit leaking. Weird?

Mountainman · **Posted:** Thu May 19, 2016 11:49 am

ok, I read on the quick learn, which maybe makes sense for the weird shift into 2nd (although my old trans did the same) , but quick learn can help with shudder? It affects the pressure applied to the TC? The up shifts and down shifts are all perfect except that first shift, which might have gotten better actually.

More on my shift into second: Both transmissions did this, and it's only noticeable when you are accelerating extremely slow when it shifts, and I don't think I've felt it when the transmission is up to full temp.

ebbnflow · **Posted:** Thu May 19, 2016 3:52 pm

The quick learn should get rid of the harsh shift if your new tranny is in good shape. It will not help the shudder though. FYI, my OG tranny started shifting harsh between 2-3 at 110k miles. I fought with it for 15k miles and finally replaced it at 125k.

Mountainman · **Posted:** Thu May 19, 2016 7:31 pm

ebbnflow wrote:

The quick learn should get rid of the harsh shift if your new tranny is in good shape. It will not help the shudder though. FYI, my OG tranny started shifting harsh between 2-3 at 110k miles. I fought with it for 15k miles and finally replaced it at 125k.

Many thanks, I'm adding a little fluid now, and going for a test drive once it gets good and hot. Or adding fluid after it gets hot anyhow. I'll report back on the shifting. Seems strange that my old transmission did the same thing, but someone had it out before me, because much to my surprise, when I pulled it it had the updated pump.

Mountainman · **Posted:** Thu May 19, 2016 11:57 pm

Ok, after battling the dipstick from H***, I finally got smart and grabbed the stick out of another jeep, and even it wiped the two holes clean EVERY SINGLE TIME. I tried fast, slow, medium, over and over again. Finally, later, I got the bright idea that since the other jeep had some PO bends in it, that if I bent my dip stick just right, it would quit wiping the holes clean every time. Fresh fluid and the sun was making it really hard to tell where the fluid was. So, after a few bends, and an un-bend, I finally have a dipstick that doesn't wipe the holes open! The bad news is, after the sun mellowed out a bit, and the fluid that I added had settled enough to quit coating the stick way up high, I am about 1.5" above full :banghead:

I added 1.5 quarts today, and probably didn't need any.

The short test drive I took seemed like the shudder was a little better, but now I'm afraid I'll be getting bubbles and more problems.

I guess I'll find out tomorrow when I try to pull a CRD over a good sized mountain pass on my extra beefy tow dolly (6-6500 lbs I guess). If it doesn't smooth out I'm going to be really disappointed, because I've read of people with stock TC's that didn't shudder at all for many miles, and only developed shudder much later (and they said they had a GDE tune).

The shift to second if feeling fine now, and all other shifts are excellent. Maybe the Eco TCM tune helps bypass the Quick Learn scenerio?

-The Eco tune has the TC locking at 35 mph, which is amazingly awesome, but why do I get zero shudder there? I guess because torque is low, and when we shift into 5th around 50, the torque is about peak?

Mountainman · **Posted:** Sun May 22, 2016 11:11 pm

The CRD tow went well. The shudder has lessened a good amount after the additional fluid, but I wasn't paying much attention to it over the weekend. I'll have to take a better read on it tomorrow when I tow heavy again, before I give my final opinion.

The Scott McLean · **Joined:** Tue Feb 15, 2011 9:19 pm **Posts:** 43

Be careful too much fluid in the transmission can cause the fluid to froth, or bubble. If the fluid bubbles, you'll burn up your transmission.

Sent from my Nexus 5 using Tapatalk

Mountainman · **Posted:** Mon May 23, 2016 9:31 am

The Scott McLean wrote:

Be careful too much fluid in the transmission can cause the fluid to froth, or bubble. If the fluid bubbles, you'll burn up your transmission.

Sent from my Nexus 5 using Tapatalk

Thanks, I think I'll try draining a quart plus however much a bottle of Dr Shudder is. Good thing I installed a drain plug

Mountainman · **Posted:** Thu May 26, 2016 11:52 pm

Drained two quarts, and then added 1.5 back :banghead:

, added anti shudder crap, it's a little better, but definitely shudders, and then yesterday it started having some strange shifting. I'll get a quick learn, but I really hope that someone can do it besides the stealership. I have yet to let them ever touch any of my vehicles.
I'll report back after the quick learn, but looks like I still have some shudder from about 50-52mph, and maybe at the shift to 6th also.

kj75 · **Posted:** Tue May 31, 2016 8:32 pm

I am having something similar (shudder / vibration on heavy acceleration from 3rd gear onwards up until 2100rpm) after a 2.3" lift.
Initially I replaced the tranny fluid and filters, and added Dr Shudder but shudder didn't really improve.

Then someone mentioned that the shudder / vibration could be the result of the lift, which puts the driveshaft angles out of correct alignment (3degree change can cause vibration). I was only getting shudder when I was driving by myself, and things greatly improved once the Jeep was loaded at the back.
Once I had 3 adults in the back, the shudder almost disapeered completely. I also lowered the transmission 1cm (tried 2cm but wasn't any better).

My final step is to replace the Ujoint this weekend which might help fix the shudder/vibration when I drive without load at the back.

KJ75

Mountainman · **Posted:** Tue May 31, 2016 9:08 pm

kj75 wrote:

I am having something similar (shudder / vibration on acceleration from 3rd gear onwards) after a 2.3" lift.
Initially I replaced the tranny fluid and filters, and added Dr Shudder but shudder didn't really improve.

Then someone mentioned that the shudder / vibration could be the result of the lift, which puts the driveshaft angles out of correct alignment.
I was only getting shudder when I was driving by myself, and things greatly improved once the Jeep was loaded at the back.
Once I had 3 adults in the back, the shudder almost disapeared completely (proof it's a driveline issue). I also lowered the transmission 1cm (tried 2cm but wasn't any better).

My final step is to replace the Ujoint this weekend which might help fix the shudder/vibration when I drive without load at the back.

KJ75

Thanks for the thoughts. After a couple of days, mine has improved a lot with the anti shudder juice, and I also noticed that when I was towing with a lot of weight on the hitch, that it was less. I can now drive all the way up to speed without any noticeable shudder if I accelerate lightly. If I push it hard it shudders lightly. I guess if the anti shudder crap lasts long term then I'm ok, but I still need a quick learn for some weird shifting. I'll report back after that, and I'll put some new u-joints in soon also, as I still have some underlying vibration. I may throw a Suncoast in also to kill two birds with one stone, as the guys running them said they helped with vibration. Then there's the Florida Billet converters for much less $$, hmm, no idea what options you have across the pond.

I'd really like to hear how your u-joint replacement goes :JEEPIN:

Mountainman · **Posted:** Wed Jun 01, 2016 11:53 pm

Now it's back after another heavy tow (about 4k lbs), and I'm starting to wonder if the light vibration I have much of the time under load, is just shudder. I guess I may have got a really bad "new" TC... It comes and goes. Or maybe it's the transmission causing the TC to shudder? I'm starting to seriously think about swapping the trans and TC again, but then I won't know which caused it. Any way to tell if it's a pump vs TC, or something else?

Mountainman · **Posted:** Thu Jun 02, 2016 12:32 pm

Ok, after more reading, I am think that I'll try a Transgo kit (valve body portion) before I give up on this Hemi TC. Can anyone verify with certainty that this kit has something to do with the pressure applied to the TC to maintain lock up? I'm thinking that I'm not maintaining proper pressure, even though I have the upgraded pump.
Stronger spring keeps pressure from leaking past a valve?

flash7210 · **Posted:** Thu Jun 02, 2016 3:32 pm

The TransGo kit is good but I don't think it has anything to do with the TC clutch.
I'd try the sonnax line pressure booster.

Do you have a Ram TCM you can try?
It seems like the RAM TCM forces the transmission to run at a higher line pressure.

Mountainman · **Posted:** Thu Jun 02, 2016 5:57 pm

flash7210 wrote:

The TransGo kit is good but I don't think it has anything to do with the TC clutch.
I'd try the sonnax line pressure booster.

Do you have a Ram TCM you can try?
It seems like the RAM TCM forces the transmission to run at a higher line pressure.

thanks, I'll check on that booster, but I hope it won't insight leaks?

I don't have a ram TCM, and I love my Gde TCM tune. I don't think GDE has a tune for the Ram TCM ??

I guess I could go rob the Suncoast and new transmission out of one of my project CRD's :jester:

But, it's a LOT of work R&Ring two transmissions in two jeeps, and I already did it once :banghead:

flash7210 · **Posted:** Thu Jun 02, 2016 6:52 pm

The sonnax booster just plugs into the pressure sensor without the need for dropping the pan. It won't cause any new leaks.

Mountainman · **Posted:** Thu Jun 02, 2016 8:40 pm

flash7210 wrote:

The sonnax booster just plugs into the pressure sensor without the need for dropping the pan. It won't cause any new leaks.

Nice, thanks again

Tracking down Shudder with a upgraded pump and new Hemi TC

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