vibration in drivetrain at low rpm in 4th and 5th gear

Ranger1 · **Joined:** Mon Oct 17, 2005 7:40 pm **Posts:** 1137

Sometimes you just have to roll up your sleeves and learn by doing. Start with some simple jobs, but call someone you know who works on cars and has changed a driveshaft ujoint or a fuel pump. If they can do that, they can change a fuel filter on a Jeep. No shame in asking for help with your vehicle when you're just starting. In fact, with the way Detroit and the dealerships are heading, it could be a skill you'll have to posses in order to keep your vehicle running.

Another alternative is to check out the local community college auto shop. Contact the department head, ask if they're willing to work on a ujoint project or fuel filter change and then work with them if they allow it. They usually have skilled mechanics as teachers overseeing the class work. Some do this kind of work on certain days. Once you learn that skill, organize your event in your area.

chadhargis · **Posted:** Tue Dec 09, 2008 1:49 pm

I love twisting wrenches and I'm pretty positive I could figure out just about any job if I had the time and access to information.

But nothing replaces experience. Even the simplest job can turn into a nightmare if you don't know the "shortcuts" that never seem to be in any of the service manuals.

I've participated in tech days for motorcycles, and it's always been a big success. One I went to, there was a guy who needed to have his valve seats ground, and that was really cool to see. The motorcycle community does this stuff quite a bit, as we all stick together and have as much fun hanging out and helping a friend repair their bike as we do riding. Can't tell you how many issues have been solved by having 5 or 6 sets of eyes and hands on a job.

ATXKJ · **Posted:** Tue Dec 09, 2008 1:56 pm

5-6 may be great for talking about work.

When it comes to turning wrenches - I think the best group is about 2 - and 1/2 the time one can only watch and hand tools because there's no room.

LIBERTYinLIBERTY · **Posted:** Tue Dec 09, 2008 2:05 pm

I HAVE A DREAM..........Anyone know if there is a Jeep dealer that is going out of business that would leave all of the shop equipment? Possibly somewhere in the mid-west(centrally located). We could make a community garage!

CRDMiller · **Posted:** Wed Dec 10, 2008 1:07 am

Installed the new style Mopar Fuel/Water separator and wiring harness.
Still shudder. Although there is MUCH less air to bleed off. My head was leaking from the heater plug (just started) and I had a fuel system big leak code, so it took priority and figured it could be related, as the two (inmotion tuning, and the leak) occurred together.

Rotated rubber, still shudder.

Next up, near tank fuel pump.
Then rear u-joints.

I snapped the head off of 3 mopar 11.9? bolts from my skid plates while trying to remove the bolts from the chassis in order to put my skids on (they came out and went in fine 2 days ago!! I took em off to clean the Salton Sea from my chassis) So I have been somewhat delayed.

fastRob · **Posted:** Wed Dec 10, 2008 10:49 am

They were busy at the Transmission shop and said they found no vibration, could not leave it overnight.
We had some road ice the next day, put it in 4WD and lots of vibration, still vibration when it went back into 2WD.
I guess the CV in the front as well as the rear will be done together.
Parts is parts, got to get me some good ones.
Spicer for the rear and whoever can do the front drive shaft, should they be balanced as well?

kb61751 · **Posted:** Fri Dec 12, 2008 7:19 am

This is a very important topic, lets not lose sight of it. I feel this is one of the last major issues of the CRD left unfounded.

chadhargis · **Posted:** Fri Dec 12, 2008 11:50 am

I've been experimenting with the shudder, and trying to feel and listen to what it's doing.

Since I've got the Suncoast and the replacement pump, I think I can rule out anything internal to the tranny.

Something I discovered that may be related is that I've always had what felt like warped rotors when gently slowing. The only thing that led me to believe it wasn't warped rotors is that it doesn't do it at all speeds, just in a narrow range.

So, this, combined with the low RPM/high load shudder, does point to something in the drive line behind the transmission. Perhaps my friend was right, it is a harmonic or something.

When Christmas is over, and I see how much money my wife leaves me, I will see if I can engage a transmission shop to replace the U-Joints and balance the drive shaft.

CRDMiller · **Posted:** Fri Dec 12, 2008 5:44 pm

All right, i've got the pump in place, and I did a few wotish in 4/5 on the freeway from 55 and 60 etc And it's still there, although something defiantly feels different. I cant put my finger on it

Regardless it still shudders in the same conditions.

You folks know you can also get it to shudder at lower seed by turning off od at 40 and goose it? 40 mph with od off is around 1700/1800 rpm it will shift like this naturally but it's gutless with od on, as soon as you put any power to it, it jumps into high 2? or maby it's just the tc unlocking (no expert here)

I often drive around 40-45 mph on inclines that would otherwise put me at 2100+ rpm with overdrive on.

Ujoints to follow in the next few days, i'm tired and my hands are all crampy :P maby i'll see what the shop wants to do it.

dirtmover · **Posted:** Mon Dec 15, 2008 1:34 pm

CRDMiller wrote:

You folks know you can also get it to shudder at lower seed by turning off od at 40 and goose it?

Yeah, I reckon it's engine speed related and figure it happens a lot more than you realise in the lower gears but you just don't feel it through the sloppy TC. By switching OD off you're allowing the TC to lock up in 3rd and every little nuance gets transmitted through the seat of your pants.

danoid · **Posted:** Mon Dec 15, 2008 7:23 pm

Engine mounts.

robotmind · **Posted:** Wed Dec 17, 2008 4:32 pm

[quote/]

I experienced the same thing with the inmotion tune. I have just recently had my u-joints replaced with Spicer grease-able u-joints in a attempt to solve the problem, but to no avail. New trans fluid and both filters with AMSOIL synthetic ATF. AMSOIL fluids in the front and rear diffs as well as the crank case. I also have the ORM ; ) as well as a provent. I have a facet lift pump (4106 I think???) hooked into the factory wiring. I have the CAT fuel filter mod with the CAT 1R - 0750 high efficiency filter. Its been about 10k miles since replacing the fuel filter and I ordered 2 new ones. Hoping that it may make a difference. I do run homebrewed bio from time to time... maybe my filter is a bit clogged. It this doesn't work I guess 'll get the Suncoast and TransGo shift kit. I just don't know what to do anymore... :roll:

[/quote]

Update,

Replaced CAC hoses with Samco silicon hoses, replaced the fuel filter (CAT 1R-0750) previous filter ca. 12k miles. More power now... more shudder too... : ( Took a ride with a friend who is a gasser mechanic at an Acura dealer. His off the cuff non-technical evaluation was that the Toque Converter was trying to unlock.... He didn't think it should cause the shudder though... I'm gonna take Danoids advice and check/replace the engine mounts. Also, gonna cut the old fuel filter open and see how well it was doing its job. Making more power now for certain. Gonna disco the battery and reset the ECU and Trans computer, relearning may help the trans cope with the additional power...

TransGo and Suncoast will be my last resort...

Cheers!

chadhargis · **Posted:** Wed Dec 17, 2008 6:47 pm

I've got the Transgo and Suncoast....and the shudder....save your money.

UFO · **Posted:** Wed Dec 17, 2008 10:05 pm

CRDMiller wrote:

You folks know you can also get it to shudder at lower seed by turning off od at 40 and goose it?

I wondered. I felt something strange Saturday coming out of the mountains (OD off), and then it was gone, never knew what it was.

bigugly · **Posted:** Wed Dec 17, 2008 11:43 pm

I thought I would give everyone an update.

I had my U-joints replaced with Napa greaseable U-joints. The vibration I felt at the 4th and 5th shift points is gone. I initially was feeling a strong vibration between 50-60 mph after the joints were replaced. It seems to have subsided. I will keep everyone up to date on the new vibration if it comes back.

MrMopar64 · **Posted:** Thu Dec 18, 2008 7:54 am

For those with the shudder, try this and tell me if its still shuddering...

Drive to the speed where the trans is in lockup (4th gear, 5th gear, doesn't matter). VERY LIGHTLY tip into the throttle (maybe no more than 10% pedal). This is most easily done on flat ground. Is it still shuddering? If its not shuddering, try tipping into the pedal more (but not so much that it unlocks/downshifts). Does it now start shuddering? That will tell me a lot. Let em know what you find (hopefully 3 or 4 people can try this simple test).

retmil46 · **Posted:** Thu Dec 18, 2008 12:03 pm

Ranger1 wrote:

Sometimes you just have to roll up your sleeves and learn by doing. Start with some simple jobs, but call someone you know who works on cars and has changed a driveshaft ujoint or a fuel pump. If they can do that, they can change a fuel filter on a Jeep. No shame in asking for help with your vehicle when you're just starting. In fact, with the way Detroit and the dealerships are heading, it could be a skill you'll have to posses in order to keep your vehicle running.

Exactly why I turned right around and bought a replacement '87 300D - except for once-in-a-lifetime jobs such as changing out a timing chain (at least for an MB diesel if treated properly), I already have the experience, spare parts, and tools needed to keep it running on my own - just a bad time right now with the economy to go thru the learning curve and expense of figuring out how to care for a different make diesel such as a VW TDI.

PhoenixCRD · **Posted:** Thu Dec 18, 2008 12:10 pm

MrMopar64 wrote:

For those with the shudder, try this and tell me if its still shuddering...

Drive to the speed where the trans is in lockup (4th gear, 5th gear, doesn't matter). VERY LIGHTLY tip into the throttle (maybe no more than 10% pedal). This is most easily done on flat ground. Is it still shuddering? If its not shuddering, try tipping into the pedal more (but not so much that it unlocks/downshifts). Does it now start shuddering? That will tell me a lot. Let em know what you find (hopefully 3 or 4 people can try this simple test).

The only time I get noticeable shuddering/bucking is after accelerating to ~55, backing off to 50 (tranny locked in 4th) then slowly tipping the pedal to maintain 4th lock up. It doesn't always cause shuddering so I figured it was the fuel supply system.

Gary

mackruss · **Posted:** Thu Dec 18, 2008 12:15 pm

chadhargis wrote:

I've got the Transgo and Suncoast....and the shudder....save your money.

I've got a clutch so i will roll backwards...

nursecosmo · **Posted:** Thu Dec 18, 2008 12:48 pm

MrMopar64 wrote:

For those with the shudder, try this and tell me if its still shuddering...

Drive to the speed where the trans is in lockup (4th gear, 5th gear, doesn't matter). VERY LIGHTLY tip into the throttle (maybe no more than 10% pedal). This is most easily done on flat ground. Is it still shuddering? If its not shuddering, try tipping into the pedal more (but not so much that it unlocks/downshifts). Does it now start shuddering? That will tell me a lot. Let em know what you find (hopefully 3 or 4 people can try this simple test).

That is pretty much what everyone has been describing. It can be achieved at 50 MPH in lockup and at 56MPH if one first shifts into 5th OD then backs off to 56 so it stays in 5th. It can be done on a flat road but only for a split second. The best place to observe the phenomenon is on a hill.

vibration in drivetrain at low rpm in 4th and 5th gear

Who is online