Thread Tools Search this Thread Display Modes
Old 03-27-2014, 07:57 PM   #1
2 Rivet Member
Air Dog's Avatar
Currently Looking...
1995 36' Classic 36
Boulder , Colorado
Join Date: Oct 2013
Posts: 99
Cummins Valve Lash

I've adjusted a lot of valves but never on a Cummins. The manufacturer recomends adjusting them every 24K miles on the 5.9L 12 valve engine. The valves tend to wear into the head reducing the valve lash. The valve lash takes up the thermal expansion so ideally the lash is 0 when the engine is hot. As the valves wear in and the lash is reduced the valves will not completely close when the engine is hot. This can lead to hard starting when the engine is hot and loss of power. In the long term it can lead to erosion to the valve seats and valves.

The first problem on the Airstream is finding a way to rotate the engine. Cummins designed a handy hole on the transmission mounting flange and a barring gear that slides in. I picked one up at the local Cummins shop for $36. (first Picture) The tool slides into the hole and engauges the ring gear on the flywheel like the starter.

There is a plug in the hole. I was told it was rubber but its actually plastic with an O-ring. Be careful prying it out as you might break the plug like I did. The hole is opposite the starter side of the engine.

Cummins also built a nice plunger on the timing gear case to locate top center on the compression stroke of the number 1 cylinder. It located right under the injector pump. Unfortunatly, the air/power steering pump is located there also. You han not reach it or see it if its even there.

I used the companion cylinder (cylinders that are TDC and the same time)technique. Rotate the engine (normal rotation) and watch the number 6 cylinder lifters. The exhaust closes and the intake starts to open at top dead center. Make a mark on the harmonic ballancer. This is the top of the compression stroke for number 1.

At this point you can adjust half of the valves. Check/adjust intakess 1,2,4 and exhaust 1,3,5. Cummins calls for .010" for the intakes and .020" for the exhaust. This must be done on a cold engine. The book says to let is sit a minimum of 4 hours.

Next rotate the engine 360 degrees based on the mark you made.

Now you can adjust the intakes 3,5,6 and Exhaust 2,4,6.

Torque the adjuster nuts to 18 foot lbs and remember to remove the barring tool before you try to start it. Pretty straight forward.
Attached Thumbnails
Click image for larger version

Name:	valve lash 007 (Large).jpg
Views:	75
Size:	92.6 KB
ID:	208391   Click image for larger version

Name:	valve lash 010 (Large).jpg
Views:	78
Size:	91.6 KB
ID:	208392  

Click image for larger version

Name:	valve lash 009 (Large).jpg
Views:	62
Size:	111.0 KB
ID:	208393   Click image for larger version

Name:	valve lash 008 (Large).jpg
Views:	82
Size:	97.6 KB
ID:	208394  

Click image for larger version

Name:	valve lash 011 (Large).jpg
Views:	76
Size:	102.1 KB
ID:	208395  

Air Dog is offline   Reply With Quote
Old 03-27-2014, 09:35 PM   #2
Rivet Master
pappy19's Avatar

2002 30' Classic S/O
Garden Valley , Idaho
Join Date: Jul 2010
Posts: 1,254
What do you do if you have a Ford 6.8 3V V-10?

2008 F-250 4X4 Lariat V-10
2002 Airstream Classic 30' w/SO #2074
2007 Kubota 900 RTV
1996 Ford Bronco
2007 Lincoln LT
pappy19 is offline   Reply With Quote
Old 03-28-2014, 07:21 AM   #3
4 Rivet Member
Dakota's Avatar
Currently Looking...
1995 36' Classic 36
Boulder , Colorado
Join Date: May 2011
Posts: 489
Images: 5
Cummins Valve Lash

I believe that engine is overhead cam. Should never need adjusting.
Dakota is offline   Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
To Cummins or Not to Cummins?? Help!! On the brink! big_john Tow Vehicles 33 03-23-2010 08:20 PM
Cummins Diesel Upgrade to Classic MH Wayne Olson Classic Motorhomes 99 01-26-2008 05:59 PM
First impressions of my new Dodge/Cummins tow vehicle idahosafari Tow Vehicles 14 04-17-2004 08:31 AM
Will 2000 Dodge RAM 2500 with Cummins 5.9L tow A/S well? idahosafari Tow Vehicles 23 03-11-2004 02:34 PM

Virginia Campgrounds

Reviews provided by

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 12:48 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.