Engine/Transmission (1998.5 - 2002) question for anyone

[bwromine]

I have a 2002 3500 2wd and it started a jerk when i shift into 6th gear. It only does it when I pull my horse trailer, never empty. I have taken it to a local dodge house and they checked on their computer and found nothing out of sorts. They read the temp of the injectors and found #1 and #2 to be about 30-40 degrees warmer (at idle) than the other four. they think these maybe failing but wanted some more input from others to make sure. Anyone go through anything like this before? I do have and edge chip on the truck and have taken it off and it does it when it is stock also. Any info would be greatly appreciated.

 

[DCreed]

youll need to give us an accurate discription of your truck ,is it bone stock or 1000 hp? any info may be helpful,ie: air filter stock,bhaf,afe,nano,ect. do u have(boost,egt,fuel press) guages? it seems the injectors are faulty and (if stock) would be beneficial to change to aftermarket upgrades anyway.

 

[bwromine]

sorry. I have a fass 95g fuel system, edge ez chip on the truck. Everything else is stock. When the truck started this problem I thought it was the lift pump and wanted toreplace this anyway, is the reason I ordered the Fass system. I still have all of the power the truck has ever had. When the jerking starts I can get into the throttle and it will stop and go on. I forgot to state that it only happens within the 58. 5 - 62 mph on speedometer.

 

[Grizzly]

It sure sounds like clutch, but why only six gear? Maybe it's something in the driveline, like U-joints. What I'm wondering is if it only happens at low RPM with a load. Have you looked at the running gear on your horse trailer?



Welcome to TDR and add your signature as soon as you can.

 

[bwromine]

Entire driveline is tight. u joints are tight. Carrier bearing has a small small amount of play. Changed the oil in rear end just 1,000 miles ago. Horse trailer is brand new. I pulled the trailer before the truck started making the jerking motion. This has me completely baffled. The motor and turbo have absolutely nochange in sound when the jerking starts. No noice from the rear of truck either.

 

[BTighe]

will it do this in 5th at the same speed?



how many miles on trans? good oil in trans?

 

[dmhollister]

Changed the oil in rear end just 1,000 miles ago.

Just a stupid question. Does your truck have a limited lip rear end? If so did you "train" it when you changed the fluid? I may be off base, but I had to do several tight figure 8 turns in a clear parking lot to "train" the limited slip clutches for the new fluid. Even with the friction modifier added to it. Just another place to consider. D

 

[bwromine]

It doesnot do it any other time other than 6th gear, uphill and 58. 5-62 mph. This is the part that is getting me. If it would happen someother time I might be able to figure it out.

When I changed the rear end oil the attendant told me that the oil in the manual transmission should not be changed, only added to. ???

I have 101,000 miles on the truck. I bought it in 03 with 33,000 on it. Have not had any other problems.

 

[bwromine]

yes it has the limited slip rear end. But the oil change was after the jerking started. Could the oil break down and now I need to dosome figure eights??

 

[Froadin]

It's past time to change the stock transmission fluid now.
Just get the factory fill stuff (cheap and easy to get it at places like Jiffy lube).
The clutch is my first guess, but the injectors could be causing this as well.

 

[bwromine]

I know it is synthetic oil you put in there but what is the weight?

 

[Froadin]

Pennziol (or Quaker state) Syncromesh.
Stuff is pretty thin, like 4 - 30, or something like that.
People running redline or royal purple run up to the 70-90w range.
I have tried most fluids now, and I am now just using the Syncromesh stuff, and changing it more often (about 20k).

Do a search, plenty to read on this subject, with a LOT of different opinions.

 

[Grizzly]

Entire driveline is tight. u joints are tight. Carrier bearing has a small small amount of play. Changed the oil in rear end just 1,000 miles ago. Horse trailer is brand new. I pulled the trailer before the truck started making the jerking motion. This has me completely baffled. The motor and turbo have absolutely nochange in sound when the jerking starts. No noice from the rear of truck either.

Even though your horse trailer is new, I'd pull the wheels and hubs out and look to see if the bearing and or brakes are adjusted properly, or try pulling someone else's horse trailer. If it's not the trailer, go on to something else. Try the differential until you can rule it out. It's a process of elimination by ruling out the simplest things first.

 

[DCreed]

u may simply be bogging the engine, shift to 6th at a higher mph

 

[GCULP]

u may simply be bogging the engine, shift to 6th at a higher mph

that would be my guess as well.

 

[bwromine]

I thought about the bogging part, but even when I shift at say 50 mph into 6th gear the truck just picks right up and pulls. I never even thought about pulling another trailer until last night. I have not had anyone try pulling my trailer yet either. That will be my next step.

 

[Boondocker]

I think you are suffering "axle wrap". Peak torque is around 1600-1700 RPM. I think you're at max torque load when you shift into 6th at that speed. This causes the leaf springs to twist, deflecting your pinion angle - very hard on the U-joint. I have heard of this problem being addresed with traction bars, something that's on my long list of things to upgrade to.



I didn't notice your axle ratio, but with my 3. 54 rings and 265 tires, I usually run up to about 65 MPH before shifting into 6th when towing, and only upshift if I can keep from lugging.

 

[dpuckett]

I agree with Boondocker- keep your RPMs up while towing. Not only does it increase airflow to the engine, it will also be easier on your drivetrain. Contrary to popular belief, low RPMs in a diesel arent always the answer. These guys have a lot of write ups for high performance semi truck driving style that I have adapted to my Dodge pickup, and it has helped some. Learn to drive by the pyrometer, and you'll save not only fuel money but your engine and drivetrain as well. Sometimes revving to 22-2400rpms will actually result in lower fuel consumption than running at, say, 1800.



Daniel

 

[Grizzly]

I thought about the bogging part, but even when I shift at say 50 mph into 6th gear the truck just picks right up and pulls. I never even thought about pulling another trailer until last night. I have not had anyone try pulling my trailer yet either. That will be my next step.

It's been a few days since we have heard from you. What have you found out is the problem.

 

[bwromine]

I have been in the hay field and working cattle since last Friday. I did pull to a rodeo last Friday night and kept the rpm's up and did not shift until I reached about 60 mph. It never did any of the jerking when I shifted at that point. However, I think I can feel a jerk starting now at about 45 mph in 5th gear. If that is the case it is about the same rpm as when I am in 6th at about 60 mph. There may be something out of balance somewhere??