Engine/Transmission (1994 - 1998) truck got slower!!!

[jnau99]

So a while back my dowel pin let go. I fixed it and screwed up the timing at the same time. I had a local shop set the timing they didnt tell me what it was at they just said they set it close to stock. They had to do it twice because the first time it came out of timing. After that the truck ran and drove again.



After all this the truck seems slower. I know because my clutch used to slip and now it dosent slip at all. I had the fuel pressure checked and it was fine. The only thing I can think of is the timing is back out. I dont want to feel like an *** going in the shop for the third time if this is not he problem. I would have set it on my own but didnt want to buy the tools. I also have been getting worse gas millage.



Boost and pyro look fine to me, the turbo dosent seem to have any play.



Also dose any one have the PN# for a speedy sleeve from a cummins dealer? I'll try searching but dosent hurt to ask.



Thanks

Justin

 

[bmoeller]

If the pump shaft wasn't cleaned well enough, the timing could still slip. Did they use the timing pin to find TDC, or use a valve to find TDC? Have heard the pin isn't always right on. Never checked myself, so I can't verify that.

 

[jnau99]

They checked it with the pin.



I went and talked with them today and they said it may have slipped again. They said sometimes they'll redo it a few times. He asked me if I got the gear back on correctely or is it off by a tooth. I'm going to check it tommrow when I put a new front main seal in.

 

[wcjp]

The timing can easily slip out if the locknut surface is not absolutely clean. Bring your truck to the next Nwbombers Bomb party. Theirs usually someone who brings a timing kit. They'll be able to advance the timing no problem.





www.nwbombers.com

 

[JGK]

The timing pin is not all that accurate. Better to find and mark it using a dropped valve. The tapered shaft of the pump and inner surface of the gear must be clean and dry. When I do it, I always do a thorough squirt of brake cleaner, moving the gear in and out with a gear puller bolt threaded into one hole, followed by compressed air, again moving the gear with the bolt. I do this 3 times. Never had one slip.



You can't get the gear off by a tooth relative to the cam gear unless you remove the gear case cover. It won't come out far enough with the cover on to uncouple from the cam gear.



-Jay

 

[Jschafer]

Maybe I miss read, but it sounds like you are going to pull the cover anyway, if you are that is the best time to set the timing, when you can remove the gear and clean every thing up perfect.



How far off has anybody found the timing pin to be I realise that the valve method done correctly is perfect but how far can the timing pin be off.



Also I assume that the truck is set with the pin from the factory?

Not being smart just curious.

Joe

 

[Andy Redmond]

He asked me if I got the gear back on correctely or is it off by a tooth. I'm going to check it tommrow when I put a new front main seal in.

Why would it matter (pump gear)? There is no woodruff key being used etc (as on the 24v or earlier 12v with no P7100. I think he refers to the cam and crank gears being at the alignment mark from the KDP gear housing R&R repair. I have done the KDP repair Justin mentions and marked all the gears, then reck'd the timing after the job was complete to find that it was spot on sometimes and that minor mark misalignment can mean timing is off.



Justin FYI. . this all presumes that the cam and crank are matched up on the marks. .



When you time with a timing gauge. You use the TDC marks mentioned (timing pin or dropped valve and mark a fixed point and the vibration dampner). You bar the engine around until you reach engine TDC then take a reading of the dial indicator/timing gauge. Then compare this mm of lift measurement to the timing recipe you are after. If its oem, then the timing pin in the pump s/b the same as the dropped valve TDC mark and theorically the timing pin. If you were trying to advance beyond stock continue to bar the engine past tdc until you recognize the lift measurement you desire on the timing gauge. Then you would loosen the pump shaft nut,remove the nut and washer, put your gear puller on and seperate the pump gear from the shaft taper. Assure the pump is still where you want it. Bar the engine counter clockwise about 60 deg. then back clockwise to engine TDC. (now the we have pushed the pump further ahead of the engine tdc and increased the timing if that's what your after).



Clean the shaft taper as described, push the gear back on. Replace lock washer, with a new one (Cummins part no 3920922 lock washer for injection pump gear/nut/shaft)

, tighten the nut to updated torq. spec of 144-160 ft. lbs. Re-ck. before re-assy, by rotating counter clockwise 60 deg. then back to engine TDC, is your lift measurement where you want it?



If so, put it back together, if not go thru the process until you get it right.





I think its timed a little slow. . I guess you will find out.



3802820 Cummins number for seal and wear sleeve kit (heavy bronze sleeve) vs. the wimpy ready sleeve.



You will also need a sleeve installer very expensive from Cummins (> $200)



Contact my friend and TDR member Mike Ames "BoomerII" Mike is a master machinist and welder and fellow gear head who appreciated the "Iron. " He has made many of the specialty tools for my business.



He's making a batch of the sleeve installers as we speak. Not sure if his pricing, but you can PM him to find out.



Andy

 

[Andy Redmond]

How the timing pin is set

J Schafer:



Yes, its set at the factory when the engine is assy. (Completed short block with the gear housing, cam and tappets installed). The num 1 piston is brought to TDC against a metal plate or dial indicator, Then the timing pin is precisely located (it will move around on the gear housing).



It can be re-adjusted in the truck, but a real pain. Its practically a necessity to remove the vacuum pump assy to gain access (much easier without the injection pump on the engine) to the two torx head fasteners, so the timing pin housing can be adjusted. If the engine is in the truck, you should use the dropped valve method to assimilate true TDC with timing pin TDC accuracy.



1/8" of vibration damper movement = approx. 1 degree of timing.





Some years ago, Piers shared with me that the timing pin can bite you if you always trust its accuracy. Its conceivable for it to be off maybe two degrees (it likely has that much adjustment).



Good luck

Andy

 

[Jschafer]

Thank you, Andy

I had heard that the dropped valve was the most accurate. But I figure that most people set by timing pin, glad to have the info.

Joe