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jimeneztrans84 · 12-11-2019, **(Subject: Cm2250 overhead set )**

I have a 2011 cm2250 and getting ready to do overhead set soon. I seen Simon's video on YouTube and he checks the engine brake with a dial indicator after he adjusted the lash. I looked up the procedure on onsite for my engine and it doesnt say to do that for my year engine. He has a cm2350. Do I have to check it with dial indicator as well? Also I dont have a in lbs torque wrench for engine brake nut so 177 in lbs equals 14.75 ft lbs should I be fine? Thanks guys

Waterloo · 12-12-2019, **(Subject: Cm2250 overhead set )**

I don't know who Simon is, or why you would need to use a dial indicator... I would purchase an inch pound torque wrench, will be more accurate than using a foot pound at those numbers. But, if it is all you have, just make sure you release all of the tension on it and then set before use.

Rawze has a good video on doing the overhead, even though it is on a CM-871, the same procedure applies, as the exhaust side is identical to yours.

Tekton makes a decent torque wrench for the money, that is what I use...

https://amzn.to/2PNkWdI

Many of the Farm and Fleet or Tractor Supply stores sell these, so you may be able to purchase locally. Prices are normally on par with internet pricing, around $40.

JMBT · 12-12-2019, **(Subject: Cm2250 overhead set )**

The dial caliper is the best way to get a measurement on the jake detent positions, and therefor head wear. I use it every time I do an overhead. I bought a cheap one on Amazon about $30 if I remember right. If you don’t have a dial you will only be able to see if you still have detent not how much.

I agree with Waterloo on the torque wrench, the ft/lb will work but if you are going to be doing your own overheads you might as well buy a small in/ft as well.

Waterloo · 12-12-2019, **(Subject: Cm2250 overhead set )**

Post a link to measuring with the dial caliper if any of you have it... Curious to see this, as I have not heard of this, nor is it in the Cummins manual.

JMBT · 12-12-2019, **(Subject: Cm2250 overhead set )**

I don’t have a link, I just put the dial on the back side of the Jake rocker and zero it out, then push it down into the detent position. Measure the travel .000 of a inch, write it down, then at the next overhead take another measurement to see how much if any detent you have lost.

You are correct it is not in the Cummins manual, but then again they also say when the detent is gone you can slightly rotate the rocker shaft to regain it.....that is a huge no, no! I think Rawze posted about it once. No detent means the valves are to high in their seats and the head is worn out, but Cummins fails to tell you that too.

jimeneztrans84 · 12-12-2019, **(Subject: Cm2250 overhead set )**

Here's a link. If I buy that 1/4 inch torque wrench and put an adapter from 1/4 to 3/8 for crows foot am I ok? Do I lose any torque going that route or buy a 1/4 crows foot I believe 13mm for Jake brake?

https://youtu.be/_tWI5pipZoA

JMBT · 12-12-2019, **(Subject: Cm2250 overhead set )**

A straight adapter will not affect the torque at all. The Crow’s foot may change it bit, but there is no other way to do it.

Rawze · 12-13-2019, **(Subject: Cm2250 overhead set )**

(12-12-2019 )JMBT Wrote: ...
they also say when the detent is gone you can slightly rotate the rocker shaft to regain it.....that is a huge no, no! I think Rawze posted about it once. No detent means the valves are to high in their seats and the head is worn out, but Cummins fails to tell you that too.

it was this post...
http://rawze.com/forums/showthread.php?t...66#pid9466

Hammerhead · 12-16-2019, **(Subject: Cm2250 overhead set )**

(12-12-2019 )jimeneztrans84 Wrote: Here's a link. If I buy that 1/4 inch torque wrench and put an adapter from 1/4 to 3/8 for crows foot am I ok? Do I lose any torque going that route or buy a 1/4 crows foot I believe 13mm for Jake brake?

https://youtu.be/_tWI5pipZoA

It's an old wives tale that extensions and adapters affect final torque, BS.
A crows foot or torque adapter adds a slight amount of leverage, thus increasing the torque applied slightly. Nothing we're doing on these motors needs to be that precise that we need to compensate for the extra 1-2 in/lbs of increased torque from these adapters.
Think of it like this, a crows foot adapter is approx 1 to 1.5" longer center to center. Let's use 1.5 for extreme. The torque wrench will be approx 18" from center to center handle. 1.5/18=0.083 or 8.3%. Now add 8.3% to 177 in/lbs and you're at 191.75 in/lbs on a hardened steel jam nut threaded into a hardened steel adjuster screw...and that's an exaggeration of measurements. Mine is less than an inch, and my 1/4" drive torque wrench is less than a foot, so I mean exaggerated!
I know someone who got hamfisted and twisted the 1/4" square drive off the torque wrench because he was expecting a big "click" out of a tiny wrench. Yeah you read that right, the torque wrench failed, not the jam nut or the adjuster screw! The measurement is as much for consistency between the adjuster said with enough tension to ensure something not coming loose, and less the metalurgy of the components.