You are here:

Truck Repair/Loose valves on NT855 big cam


I have a NT855 cummins big cam, sn: 11104954, I have changed out the injectors and reset valves. After starting engine and checking, I am having problems with slack in two valves. Checked pushrods on that cylinder, pushrod  is straight. What is your suggestion on what might be my problem.

The first thing that comes to my mind is you were on the wrong cylinder. Example your on A and you can adjust 1 or 6 you adjusted 1 when it was really on 6. Just a thought there. If that's not the case let me know i'll dig out the book and see where we can go with it.

Truck Repair

All Answers

Ask Experts


Jeff Drumm


I Can answer any question pertaining to semi trucks and trailers. Have no experience in the automotive field so not able to help in that area.


My experiences in Semi Trucks is. I own my own truck and i presntly maintain a 80 truck fleet. Can handle any questions pertaining to a truck have tore apart and rebuilt every aspect on them. Fleet I deal with is Mainly Volvo trucks and a handful of freightliners. Work on automated transmissions on a daily basis along with carrier apu's. With engines my specialty is the 60 series Detroit but do work on the cummins isx the n-14 and the ism. and also the Volvo engines.

Have a College Degree from university of northwestern ohio in diesel and agriculture mechanics. Have 10 years behind the wheel driving a truck and 4 years working on trucks full time. Also have grown up on a farm so have been tinkering on trucks and tractors all my life.

Awards and Honors
I've gone through online schooling and have received certificates from webb wheel, Timken and Volvo academy.

©2017 All rights reserved.