Engine/Transmission (1994 - 1998) valve lash

[Mhannink]

well im looking to do my valve lash adjust one of these days when we are allowed in the shop at school. i looked on all data for a procedure to set the lash and all i found were specs and not very good directions i was wondering if any of those that have done it can give me a trick to it. also is spec the best or is there a tweak to the lash that i can get a little extra benifit from.

 

[Joe G.]

The service manual has a pretty good description on what to do. I use a dial indicator rather than a feeler gauge.

 

[Vaughn MacKenzie]

MHannick, read my post on this thread (post 14) https://www.turbodieselregister.com/forums/showthread.php?t=156354

 

[JGheen]

That seems to be a much better way of finding TDC by using the valve overlap as you suggeted in that thread. I will have to try that next time and see how close my TDC mark is to that method.



Joe

 

[flyairam]

There are as many ways as there are guys, but here's how I did mine.



Got a big wrench from Harbor Freight that fits the fan hub. This is good because it's easier to use than the barring tool. The belt will act as a ratchet, just ratchet the engine over until the timing pin on the back of the pump drops into its hole (go slowly, you don't want to sheer it off). Now take some white-out from your wife's office, and make a mark on the front pulley right by the crank position sensor. Bingo, that's the last time you'll have to use the timing pin (don't forget to pull it back out now).



Do half your valves. Ratchet the engine over exactly 360 degrees, until the mark is lined up again, then do the other half.



The white-out mark and wrenching from the fan hub will save you tons of time next time you do your valves (at the recommended 25,000 mile interval).



RAH out.

 

[SRehberg]

I use the valve overlap method and it works easily. You can use the alternator to turn the engine, but everything is in reverse so keep it in mind. Using the alternator, you can easily turn the engine CCW but the other way it won't work. Try it, you'll find it's easy to do.

 

[biggy238]

Do half your valves. Ratchet the engine over exactly 360 degrees, until the mark is lined up again, then do the other half.

That's just vague enough to be dangerous.







An easy way to check that you are adjusting the right valve at any time is to give the rocker a shake and spin the pushrod. If they are free, you can adjust that valve.

 

[Joe G.]

That's just vague enough to be dangerous.







An easy way to check that you are adjusting the right valve at any time is to give the rocker a shake and spin the pushrod. If they are free, you can adjust that valve.

I'm not sure you can do that. The lifter may be on the clearance ramp a little. The service manual has an illustration that shows which valves can be adjusted in each of the two positions. Nothing to it. Only two stops for the whole job instead of six.

 

[Mhannink]

thanks all for the replys that last one by biggy238 helped the most thats what i was wanting to know most was whether or not the it all had to be loose and the brought down to the correct tolerance. i assume that w/ the rocker ''free'' where the pushrod moves and the rocker moves then when you put the feeler guage in there and tighten it down it will be right on the money. thanks again all for the replys and correct me please if i am seeing this wrong.

 

[Joe G.]

If there is some wear so that the top of the valve stem is rounded a little and the end of the rocker is dished a little then a feeler gauge will not be accurate. I don't know if that is a problem on our Cummins engines or not, but it is on other engines. A dial indicator will measure the exact clearance as close as possible. Also if you tighten the adjustment too much it will compress the valve spring. Also you can dent your feeler gauge. There is a certain feel to it when it's right. It should grip the feeler gauge a little so there is some friction when you pull it, but it should not take much of a pull to move it. Tightening the lock nut may change it a little so you have to check it after the nut is tightened. It's not a hard job, but it's not a cut and dried procedure either. It's a lot easier on this engine than some others. For example an old Chevy six valves had to be adjusted with the engine warm and running.

 

[biggy238]

HHmmm I should have said in conjunction with the proper order... . I got about half way back on my valve job and lost track of which valve I was on... . One valve was tight and the other would spin.



There are a few resources for the order. The instruction I used:



http://www.dodgeram.org/tech/dsl/valve_adj/12_valve.html





I also recommend taking the aluminum name badge plate off the top (not the valve covers) and washing the top of the engine down. This will help keep crap out of the head and promote a good seal when you put the valve covers back on.

 

[Mhannink]

HHmmm I should have said in conjunction with the proper order... . I got about half way back on my valve job and lost track of which valve I was on... . One valve was tight and the other would spin.



There are a few resources for the order. The instruction I used:



http://www.dodgeram.org/tech/dsl/valve_adj/12_valve.html





I also recommend taking the aluminum name badge plate off the top (not the valve covers) and washing the top of the engine down. This will help keep crap out of the head and promote a good seal when you put the valve covers back on.

your not talking about the i. d. badge on the gear case are you also thanks for that site that will help a lot

 

[biggy238]

No, the single aluminum Dodge Cummins plate that runs back the top of the motor that's held by just two bolts. If you take it off, it will just be the six individual valve covers left underneath. Pull that piece of aluminum off of there and wash real well down the intake side of the valve covers and between each one of them and them let it dry. Then go ahead and pull your valve covers for the valve job. This will get alot of crap out of the way that could get into your engine or even just under the cover gaskets and cause a bad seal... Mine was covered in dirt/dust and Maple seeds.

 

[Mhannink]

oh ok well i washed my engine a couple times already in the last month after i went mudding so its pretty clean and anyways im doing this in the school shop and i don't know how they would take to me washing it down first might be a pain but thatnks for the suggestion

 

[Valv]

I have a question now, what do you do to get to the locking pin on IP ?



I have all sorts of stuff in front of mine and I definitely cannot get to it easily, heck I cannot even put light on it with flashlight, do I REALLY have to have it in to get timing done ?

 

[Vaughn MacKenzie]

Valv the timing pin is useful for setting pump timing, but not necessary at all for valve adjustments. Timing is a whole different subject, there are other threads on that if you look around the 12-valve forum. I could give you some pointers on that. The timing pin is a bit of a bear to find, and then a bear to pull in and out (often it's stuck from years of grime) and thirdly it can be a bear to spot the hole it pops into at TDC.



Vaughn



EDIT: if you're talking about your '99 there is no timing pin, they only apply to the 12-valve trucks. Timing on 24-valve trucks is done electronically.

 

[Valv]

Thanks Vaughn, yes I was talking about my 12v.