Free 7 Day Trial RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Free 7 Day Trial ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > POWER TRAIN GARAGE FORUMS > Caterpillar Engine Forum
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
 
Thread Tools Search this Thread Display Modes
 
Old 10-31-2021, 01:38 PM   #1
Senior Member
 
Newmar Owners Club
Freightliner Owners Club
Join Date: Jun 2016
Location: Odessa, Tx.
Posts: 635
Dissecting my dead cat

A year ago I over revved my cat 3126 going downhill and it dropped a valve in number six cylinder.

I purchased a used engine had that installed and life is good again.

My project of the day was to disassemble the dead cat so I can free up that much floor space and quit walking around it.

My initial thoughts and findings are as follows

1. It really isn't that large of an engine. The block is only 31 inches long while the 1981 Ford six cylinder in the pick up is 29.

2. It was in really good shape all the bearings are good. Probably would have ran forever if I had not dropped a valve due to too high in RPM.

3. The piston is a two-part assembly that's a new one on me

4. There's a hole at each of the four corners of the engine block where you can install the dipstick tube depending on your installation.

5. If anyone wants a part to use as a wall hanger let me know.

6. You're not going to strip out the oil drain plug. They put a really big bung on the inside the pan to use as female threads
__________________
John and Sue from W. Texas
2001 DSDP, 3126B Cat

"the Oilfield PAID me to retire, so I did" :-)
JNSNWT is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 10-31-2021, 01:43 PM   #2
Senior Member
 
Newmar Owners Club
Freightliner Owners Club
Join Date: Jun 2016
Location: Odessa, Tx.
Posts: 635
Hereís a few pics.

If anyone is interested in a special shot let me know and Iíll try to get a picture of it for you
Attached Thumbnails
Click image for larger version

Name:	10926062-AB9B-4DD0-9248-766DE8B8C402.jpg
Views:	39
Size:	282.0 KB
ID:	347732   Click image for larger version

Name:	9CA132C9-844F-49C2-B5D5-1520CB4F4571.jpg
Views:	30
Size:	244.0 KB
ID:	347733  

Click image for larger version

Name:	5EEBA68E-853E-49DA-8B40-8D0E092D3916.jpg
Views:	35
Size:	193.4 KB
ID:	347734   Click image for larger version

Name:	image.jpg
Views:	37
Size:	327.0 KB
ID:	347735  

__________________
John and Sue from W. Texas
2001 DSDP, 3126B Cat

"the Oilfield PAID me to retire, so I did" :-)
JNSNWT is offline   Reply With Quote
Old 10-31-2021, 01:54 PM   #3
Senior Member
 
Join Date: Sep 2010
Location: ,Louisiana
Posts: 541
why not refresh it in case you drop another valve! you don't have to be in a hurry just work on it when you are bored !
swampdog2 is offline   Reply With Quote
Old 10-31-2021, 06:17 PM   #4
Senior Member
 
Newmar Owners Club
Freightliner Owners Club
Join Date: Jun 2016
Location: Odessa, Tx.
Posts: 635
I seriously considered fixing it and selling it. I didnít have to price many parts to realize it was not cost effective. These are old engines that have a very limited market. I paid $10k for a used factory built with 50k verifiable miles when I could have bought one that had been ďgone through ďand had anything that needed to be replaced put in new(supposedly)for $6k.

While talking to the 6k seller I kept remembering the you tube videos Iíve watched of engines being rebuilt in the dirt without torque wrenches or micrometers.




Plus Iím trying to declutter the shop
__________________
John and Sue from W. Texas
2001 DSDP, 3126B Cat

"the Oilfield PAID me to retire, so I did" :-)
JNSNWT is offline   Reply With Quote
Old 11-03-2021, 09:31 PM   #5
Member
 
Join Date: Jul 2017
Posts: 67
What rpm did you hit that caused the problem?
blewis9991 is offline   Reply With Quote
Old 11-04-2021, 09:28 AM   #6
Senior Member
 
Newmar Owners Club
Freightliner Owners Club
Join Date: Jun 2016
Location: Odessa, Tx.
Posts: 635
Honestly donít know.
I heard it drop at least one gear and the motor was screaming got my foot on the brakes then looked at the tach to see it between 5 and 6 oíclock.
__________________
John and Sue from W. Texas
2001 DSDP, 3126B Cat

"the Oilfield PAID me to retire, so I did" :-)
JNSNWT is offline   Reply With Quote
Old 11-04-2021, 09:31 AM   #7
Senior Member
 
Join Date: Oct 2014
Posts: 4,145
Quote:
Originally Posted by JNSNWT View Post
Honestly donít know.
I heard it drop at least one gear and the motor was screaming got my foot on the brakes then looked at the tach to see it between 5 and 6 oíclock.

Have you had the Allison ECU checked. It should prevent over-reving as part of its programming.


So, even if you use the down arrow to 1st gear at, say, 60 MPH, it will NOT over-rev the engine, but drop to lower gears only when it will not overspeed the engine.
__________________
Brett Wolfe
Ex: 2003 Alpine 38FDDS. Ex: 1997 Safari Sahara. Ex: 1993 Foretravel U240
wolfe10 is online now   Reply With Quote
Old 11-04-2021, 09:59 AM   #8
Senior Member
 
Rob_M's Avatar
 
Join Date: Dec 2019
Location: Texas
Posts: 1,135
Quote:
Originally Posted by wolfe10 View Post
Have you had the Allison ECU checked. It should prevent over-reving as part of its programming.


So, even if you use the down arrow to 1st gear at, say, 60 MPH, it will NOT over-rev the engine, but drop to lower gears only when it will not overspeed the engine.

Thatís exactly what I was thinking. Itís supposed to be impossible to downshift an Allison and over-rev your engine.
As a matter fact on my work truck when I use the pac brake it shows the transmission digital indicator going to 2 when Iím slowing down even if Iím running 50 mph. Itís definitely not in second gear yet and wonít go there unless my speed slows enough.
__________________
Rob & Laura
2002 American Tradition 40', 431hp Banks PowerPack
Mid-South TX
Rob_M is offline   Reply With Quote
Old 11-05-2021, 09:34 AM   #9
Senior Member
 
Newmar Owners Club
Freightliner Owners Club
Join Date: Jun 2016
Location: Odessa, Tx.
Posts: 635
I did go to my local Allison authorized shop and ask about eliminating the automatic downshift when the exhaust brake is energized. The shop foreman said heíd never had that request but ďbring it in and weíll look at it and decide if itís possibleĒ

I translated that to mean ď let us get on your hourly payroll and weíll call somebody to find out how to do itď


I need to call Allison tech line and hear the factory version of what it takes to eliminate the auto downshift.
__________________
John and Sue from W. Texas
2001 DSDP, 3126B Cat

"the Oilfield PAID me to retire, so I did" :-)
JNSNWT is offline   Reply With Quote
Old 11-05-2021, 09:39 AM   #10
Senior Member


 
Join Date: Aug 2011
Posts: 4,650
Quote:
Originally Posted by JNSNWT View Post
I did go to my local Allison authorized shop and ask about eliminating the automatic downshift when the exhaust brake is energized. The shop foreman said heíd never had that request but ďbring it in and weíll look at it and decide if itís possibleĒ

I translated that to mean ď let us get on your hourly payroll and weíll call somebody to find out how to do itď


I need to call Allison tech line and hear the factory version of what it takes to eliminate the auto downshift.


I donít think you want to eliminate it, in every instance Iím aware, the transmission is smart enough to DELAY the downshift from happening, IF it would overrev the engine.

Maybe check to see if your transmission needs to be re-flashed with latest firmware.
pasdad1 is offline   Reply With Quote
Old 11-06-2021, 12:07 AM   #11
Cat
Senior Member
 
Join Date: Jan 2005
Posts: 1,287
I know on some transmission it will prevent a overspeed if you try to downshift it manually and it won't downshift automatically and overspeed--- but if you have selected a max gear like 4 speed and then proceed to go downhill it is possible overspeed the engine. Safe Travels.
Cat is online now   Reply With Quote
Old 11-06-2021, 12:27 AM   #12
Cat
Senior Member
 
Join Date: Jan 2005
Posts: 1,287
I know on some transmission it will prevent a overspeed if you try to downshift it manually and it won't downshift automatically and overspeed--- but if you have selected a max gear like 4 speed and then proceed to go downhill it is possible overspeed the engine. Safe Travels.
Cat is online now   Reply With Quote
Old 11-10-2021, 08:06 PM   #13
Senior Member
 
gatorcq's Avatar
 
Freightliner Owners Club
Join Date: Apr 2004
Location: Foothills, Yuma, Az
Posts: 1,171
3260 RPM is the Overspeed Limit. With you hit it the ECU will shut it down. A computer is needed to remove the fault
__________________
Dale&Susan, 08 Alfa Gold, DaGirlsRv Blog
2015 F-150XLT_2000W Solar_600 AmpHr Lithium
Magnum_MSH 3012 & PT100
gatorcq is offline   Reply With Quote
Old 11-11-2021, 07:54 AM   #14
Senior Member
 
Newmar Owners Club
Freightliner Owners Club
Join Date: Jun 2016
Location: Odessa, Tx.
Posts: 635
Quote:
Originally Posted by gatorcq View Post
A computer is needed to remove the fault
Wagner Cat in Albuquerque didnít mention clearing any codes when they replaced the engine but thatís probably considered ďusual and customaryĒ so it wasnít mentioned.


I did call the Allison help line and was told to contact the local Allison service center which I had previously spoken with and didnít get a warm fuzzy feeling about.


Odessa Texas is an oilfield town that pays good money but the flip side is it costs more to live here. Rent is higher, cars cost more and services cost more.
Iíll call an Allison dealership 150 miles away in Lubbock which is a farming/college town an see what they say.
__________________
John and Sue from W. Texas
2001 DSDP, 3126B Cat

"the Oilfield PAID me to retire, so I did" :-)
JNSNWT is offline   Reply With Quote
Reply

Tags
cat



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
Dead dead dead batteries...help! RebelSouls Newmar Owner's Forum 56 04-14-2021 12:46 PM
Dead...I mean dead! Hi-Laker Class C Motorhome Discussions 4 05-23-2019 08:29 PM
Consequences of Dead, DEAD batteries? MarkofSJC Class A Motorhome Discussions 45 12-04-2012 08:32 PM

» Featured Campgrounds

Reviews provided by


All times are GMT -6. The time now is 07:08 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2022, vBulletin Solutions, Inc.