Engine/Transmission (1994 - 1998) Clutch Jerk

[ccsial]

I have a 97 2500 5 speed. It has 60,000 on it. Last winter I noticed a jump or lurch when letting out the clutch in 1st. This year it is worse. It gets better as the truck warms up. Yesterday it started to lurch going into 2nd. I'm wondering if it could be the hydraulic system or the clutch itself. any ideas or experiences?

 

[SRath]

If your rear main seal is leaking, eventually the oil will find its way onto the clutch and cause it to be grabby like that, just like contaminated brake shoes or pads. It won't get any better, either, just worse.



While other things can cause similar symptoms, like a throwout bearing sticking, I think the hydraulics are pretty much good or bad with no in-between on these trucks given the reservoir has sufficient fluid and is not leaking. There is no adjustment.



And wow! Only 60k miles on a 97? Are you ever going to break that cummins in?

 

[hsmith]

Maybe the problem with the clutch. Lack of use.

 

[ccsial]

I suppose it could be lack of use although it didn't start this until last year. It sits for 2 or 3 weeks a lot, especially in winter. It has not been in the snow very often. I use it when I need to haul something and for vacations in the summer towing our ATV's. It pulls a dump trailer a few times a year when I haul gravel for my trails on the property here.



I kind of wondered about a rear seal. I guess I'll have to take it in this spring. I wonder how big of a job the seal is. I'll probably replace the clutch as long as it is apart. My wrenching days are pretty limited at my age with arthritus. Pretty much limited to oil and filter changes on the truck.

 

[SRath]

Honestly, as long as it isn't really bad, I would personally let it go until I had better reason to spend that kind of money. A couple of grabby engagements before it settles down, warms up, and smooths out is something my bank account could live with compared to a new clutch on a 60k miles truck.



Some engine oils are more prone to cause seal leaks than others. Especially seals that see infrequent use and can get a bit hard and dry. That's if your problem is even in the seal.



For example: I always used Mobil1 synthetic in everything from my cars and trucks to my racebikes. It is really good oil. However, all of those vehicles soon shared one thing in common: oil seal and gasket leaks.



I switched to Amsoil years ago because it is an even better oil than Mobil1. Believe it or not, I quickly noticed in many instances that my oil seal leaks were gone or slowed way down. This was on several vehicles and was not my imagination.



The last time I changed my Dodge's oil, I had just been laid off and simply could not afford the $130 that an Amsoil change would cost. Mobil had just come out with a new synthetic just for these diesels and it claimed to have seal conditioners (if I recall correctly) and was MUCH less expensive than the Amsoil (which is getting downright ridiculous in price). So I tried it and it is still in my crankcase. Well, what didn't leak out is still in my crankcase anyway...



Yup. Even the "new and improved" Mobil diesel synthetic immediately started seal leaks again where I had none with the Amsoil. My next change will be to Rotella synthetic unless I win the lottery and can afford Amsoil once again.

 

[hsmith]

If it's any consolation, I recently installed the SB 13" 475 hp, I think, rated clutch. Slipped until I got it broken in and now is a tad grabby. Not a problem for me, surely don't want one slipping towing the fiver over the high country.

 

[RHestand]

When I was a young man I had a lot of old home built hot rods and chattering clutches were not that unusual. What I tried before tearing into it was slip/burn the clutch a "LITTLE". Sometimes it helped, sometimes it didn't. I don't ever remember it having made it worse.
I would get up to speed (35-40 mph) in top gear, give it about 1/2 or 3/4 throttle, then push the clutch peddle in just enough until you could hear the clutch slip. I would do this 2 or 3 times, stopping each time to see if it was any better. After about 3 times with no improvement I'd start thinking about getting it up on jack-stands and some up close inspections.
Ray

 

[GAmes]

I'm trying to remember when I had about 60k on mine. Must have been around '01, before I started transporting trailers. To think, I just bought a "low mileage" 12 valve out of a '98. It has (I'm told) 130k on it, and the rear main seal leaks. Easy fix when the engine is removed though.



If your seal is leaking, the oil will drip from the small slit at the bottom of the bellhousing. Mine didn't leak until it had well over 400k on it. However, age apparantly has something to do with it if my '98 engine is typical.

 

[SRath]

BTW: the title of this thread "Clutch Jerk" is completely irresistable. Might be my next CB handle... :-laf

 

[ccsial]

Honestly, as long as it isn't really bad, I would personally let it go until I had better reason to spend that kind of money. A couple of grabby engagements before it settles down, warms up, and smooths out is something my bank account could live with compared to a new clutch on a 60k miles truck.



Some engine oils are more prone to cause seal leaks than others. Especially seals that see infrequent use and can get a bit hard and dry. That's if your problem is even in the seal.



For example: I always used Mobil1 synthetic in everything from my cars and trucks to my racebikes. It is really good oil. However, all of those vehicles soon shared one thing in common: oil seal and gasket leaks.



I switched to Amsoil years ago because it is an even better oil than Mobil1. Believe it or not, I quickly noticed in many instances that my oil seal leaks were gone or slowed way down. This was on several vehicles and was not my imagination.



The last time I changed my Dodge's oil, I had just been laid off and simply could not afford the $130 that an Amsoil change would cost. Mobil had just come out with a new synthetic just for these diesels and it claimed to have seal conditioners (if I recall correctly) and was MUCH less expensive than the Amsoil (which is getting downright ridiculous in price). So I tried it and it is still in my crankcase. Well, what didn't leak out is still in my crankcase anyway...



Yup. Even the "new and improved" Mobil diesel synthetic immediately started seal leaks again where I had none with the Amsoil. My next change will be to Rotella synthetic unless I win the lottery and can afford Amsoil once again.

I think that waiting is not a bad idea. I can live with some jerk. Summer is when I use it the most. I called it jerk because it is more vilolent that what I have experienced on other vehcles that I would call chatter.



I have 3 diesel tractors and run Delvac one in them all but I run Rotella T in the truck due to the high cost and 12 qts. The three tractors use 13 qts all together and I do them once a year. I may have to try that new Mobil one. I'll call the supplier where I get my delvac from.



Thanks for all the input guys. If I hear "clutch jerk" I'll call ya Srath, I'm wirebender.

 

[SRath]

Hey wirebender, just to reiterate, I definitely would not recommend that new Mobil1 or any Mobil1 if you are trying to avoid or stop seal leaks. It is their products that I have trouble with oil leaks when using. Switching to their new stuff this last oil change has brought increased oil leaks just like the previous Mobil Delvac1 caused in my cummins and their regular Mobil1 caused in other vehicles.

 

[ccsial]

Hey wirebender, just to reiterate, I definitely would not recommend that new Mobil1 or any Mobil1 if you are trying to avoid or stop seal leaks. It is their products that I have trouble with oil leaks when using. Switching to their new stuff this last oil change has brought increased oil leaks just like the previous Mobil Delvac1 caused in my cummins and their regular Mobil1 caused in other vehicles.

Thanks SRath, I misunderstood. Do you have an opinion on Shell Rotella T? That's all I have ever used in the truck.



I guess I'm glad I didn't use Delvac 1 in the truck. I have not had oil leaks in the tractors with it so far. My 83 Ford 1910 has 1200 hours on it. The others are much less.

 

[SRath]

This is all just my opinion

No, I haven't tried Rotella in anything I own, though plenty of the company-owned fleet tractors I have driven a couple million miles over the years were serviced with Rotella. Probably most of them, and I never had any oil-related problems.



Rotella makes a synthetic diesel formula, too. I went "eeny meeny miney moe" when choosing between it and the similarly priced new Mobil1 for diesels this last time and probably chose wrong. All I really wanted was to continue to use the Amsoil, but between the high price and having to order it and wait, I tried something new and less expensive.



I saw last evening that the new farm store down the road has a few Amsoil products on the shelf, including the 15W-40 Heavy Duty Diesel & Marine oil for $30 gallon, which is better priced than what I pay the local Amsoil dealer for the stuff I use, which has always been their premium ($$$) Series 3000 5w-30 diesel oil. I prefer it, especially in this sub-zero weather, though I use it year-round.



When we raced motocross, I was signed up as a dealer and sold quite a bit of Amsoil to my fellow racers, but never made any significant money doing it. Not even enough to cover the cost of what I used myself. Their 2-stroke and gearbox/4-stroke oils can't be beat. The annual cost of being a dealer requires more than just my personal use nowadays to offset, and shipping is too expensive. They hurt themselves with their Amway/Avon/Mary Kay Cosmetics type of marketing. Few people want to wait for an oil order or pay excess shipping or track down a part-time middle man even though those same costs are factored in on retail store oils. There is also the serious issue of not being able to find it if or when you need it when travelling. You must carry all you might need for any reason with you.



The only cost-effective way I can see to continue to run Amsoil in my dodge, for me anyway, would be to bite the bullet and invest in a bypass oil filter system, which is a great idea anyway. Then it becomes very cost-effective and can go a very, very long time between oil changes as long as you do oil sampling and regular premium filter changes. And by "premium filter" I mean Amsoil filters that cost about $30 each! Hence the "$130+ oil changes" I mentioned earlier ($9 per quart for the Series 3000 and $30 for the filter PLUS shipping). More like $140 or $150.

Heck, that's almost the same cost as a tank of nasty ULSD diesel fuel nowadays once you factor in the additives it needs to sustain life in a 12-valve...



The one Amsoil product that does not impress me at all is their tubes of chassis grease. If you hang your grease gun on the pegboard loaded with it, you will eventually find a runny, oily, red puddle on the floor under it. That doesn't inspire confidence, and the Mobil1 synthetic grease doesn't separate like that... Amsoil needs to work on that.



I may very well try the Rotella synthetic next time myself.

 

[khalsey]

My truck sits for 4 to 5 months every winter since new and has 72,000 miles on it now. The clutch usually a little grabby until driven some. I pull a 15,500 # 5th wheel about 5 or 6 thousand miles a year and as long as it doesn't chatter when backing the trailer I consider it good.

 

[SRath]

Good point, khalsey. When you consider it takes only an overnight or so in humid or wet weather for brake rotors to flash rust, I can fully understand a flywheel and pressure plate doing the same over an extended period.



maybe you need to oil them... (just kidding of course)

 

[ccsial]

Thanks for the info SRath. I don't know any Amsoil dealers so I never tried it. I hear good things though.



Khalsey: Thanks, It sounds like I need to drive my truck more.