Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A Motorhome Discussions
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
Thread Tools Search this Thread Display Modes
Old 03-30-2016, 11:18 AM   #1
Junior Member
Join Date: Mar 2016
Posts: 3
Need info on Chevy 454 and TH400...

I recently bought a 1987 Country Camper motorhome. It has the Chevy 454 and TH400. I bought it in Vancouver, Washington. When I bought it I was told by the PO that the original transmission lost reverse. So he bought a "Craigslist rebuild" (I know, I know). There was no pan gasket on the trans, and it again had NO REVERSE. This is how it was when I bought it. I put a pan gasket in the transmission and filled it with ATF and let it run in PARK for a while before driving it. It seemed to go forward fine but still had no reverse. I drove it to Welches, Oregon before it started bogging down really bad and backfiring. I pulled over, and then it would NOT MOVE. The motor just revs in any gear.

Thankfully, I had purchased AAA RV PREMIERE, and after spending a bitterly cold night atop Mt. Hood with no heat (batteries died) and no blankets, I got it towed home.

I got another TH400 given to me for free. It is a 1973 CJ model from a C30 or a motorhome. My mechanic friend said that if it ran when it was pulled, it should be good to go ( I am told it ran 5 years ago when pulled. It sat inside a woodshed with only 3 sides. I am planning to replace the front and rear seals, pan, filter, pan gasket, torque converter and replace fluid with new HIGH TEMP ATF. Also new 1350 stall 13" converter. It is full of fluid and the fluid looks good).

ANY ideas as to what else to do to the trans?

Also, I would like to get more torque and HP from the 454 and possibly improve mileage. Thinking a Lunatic cam, Aluminum RPM Air-gap or Torker-II intake, MSD distributor, stock oval-port heads (049?), headers and a good exhaust

1987_CC32 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 03-30-2016, 01:30 PM   #2
Moderator Emeritus
Bruce C's Avatar
Nor'easters Club
Fleetwood Owners Club
Workhorse Chassis Owner
Join Date: Dec 2011
Location: NH
Posts: 5,100
Have the trans rebuilt, don't go to the trouble of putting one in with just word of mouth that it's good. As far as the 454 having more power and torque, save your money the 454 will serve you well as is if it's a good engine. You'll get 7mpg perhaps a tad more but doing what you mentioned will not help you out no matter what you do. I've owned that engine and was completely happy with the performance and the coach was larger. My advice rebuild the trans. and enjoy the ride. Good luck with your choice.

Bruce & Nancy
FMCA F280542
2004 Bounder 35E
US Navy Vet.
Bruce C is offline   Reply With Quote
Old 03-30-2016, 02:11 PM   #3
Senior Member
TonyMac's Avatar
Monaco Owners Club
Join Date: Oct 2014
Location: Layton, Utah
Posts: 670
If you got the pan off, drill a hole in it and install a drain plug. The drain plug is a hollow 3/4" bolt, threaded on the outside and inside. The threaded outside is what holds it to the pan, with a gasket and a bolt on the inside of the pan. The threaded inside of the big bolt is the removable plug that the fluid drains thru. I drain my fluid every 25k and change the filter every 50k. I threw away the inner plug and installed a tranny temp sending unit. So now I can monitor the temp of the fluid in the pan, the hottest fluid in the tranny. When you remove the sending unit to drain the fluid, hold the larger bolt to keep it from rotating.
TonyMac is offline   Reply With Quote
Old 03-30-2016, 04:30 PM   #4
pro_coupe 34's Avatar
Join Date: Nov 2012
Location: Pa.
Posts: 69
Take that 400 trans and get it rebuilt cost around 750 to 1 gran but worth every dollar. For that 454 there like bullet proof
pro_coupe 34 is offline   Reply With Quote
Old 03-30-2016, 04:57 PM   #5
Senior Member
stepside454's Avatar
Join Date: Jan 2011
Posts: 856
As far as the engine itself . Headers are always an improvement , but do yourself a favor & spend the money on food quality heavy duty headers with heavy flanges or you'll regret it . An RV type cam such as the Edelbrock performer would be some imprint as well as a Performer Intake, ( not the Petformer RPM). A good investment is always a good tune up , & maybe an upgraded HEI distributer.
stepside454 is online now   Reply With Quote
Old 03-31-2016, 05:28 AM   #6
Join Date: Nov 2015
Posts: 33
A simple cam,intake & 650-750 carb will be night and day on a stock 454 truck/MH engine. A simple port, polish & gasket matching of the intake/exhaust runners will be more than sufficient for sub 4500rpm RV duty. Headers, cat delete & Flowmaster mufflers could come later on, but as mentioned don't cheap out on them. Cheap headers warp & leak every time, especially under hot HD use such as MH's.
This should get you +75hp relatively easily, in which I'd want a known good transmission to handle the hp/tq and weight of MH...... Biggest oil cooler you can fit as well😉👍
BCRacing24 is offline   Reply With Quote
Old 03-31-2016, 02:23 PM   #7
Senior Member
hochmuth1957's Avatar
Ford Super Duty Owner
Join Date: Aug 2013
Posts: 167
I would not trust an auto trans that's been sitting around either. In fact I have a couple on my shed that I know for sure were fine when I took them out of vehicles I scrapped and I plan on rebuilds before I reuse them. Its just not worth getting stuck somewhere if something decides to fail. As for the 454, if it was me I'd give edelbrock a call and let them recommend cam, intake and carb as a set. When I rebuild I'm in the habit of also having .030 shaved off the heads for a little extra compression as well.
Just my 2 cents.
hochmuth1957 is offline   Reply With Quote
Old 03-31-2016, 07:02 PM   #8
Senior Member
PCarillon's Avatar
Join Date: Jul 2014
Posts: 187
I hope you mean your using Dextron 3/Mercon fluid not ATF
Paul & Kim Carillon
2005 Pace Arrow 37C
8.1 w/Allison
PCarillon is offline   Reply With Quote
Old 04-02-2016, 07:20 AM   #9
Mr. Hipster's Avatar
Join Date: Jan 2014
Location: Milwaukee area/central Idaho
Posts: 88
Wow, just wow.
Mr. Hipster is offline   Reply With Quote
Old 04-02-2016, 08:25 AM   #10
Senior Member
vapor3000's Avatar
Join Date: Jan 2012
Location: NE Oklahoma
Posts: 421
I would say a rebuilt TH400 done by an experienced OH shop and a NEW torque converter is a must if you plan to keep the MH. A bulletproof addition to these TH400's is a Gear Vendor overdrive unit that bolts to the rear of your transmission. You will reduce your cruise engine rpm with this addition.

As far as the engine, I would keep it just like GM built it. Keep your cast iron headers, just be sure you have a 3" dia exhaust system with low resistence mufflers which is inexpensive. Be sure your plug wires are good and consider a HEI distributor. A good tune will go a long way to improve your engine performance rather than spending a bunch of money on aftermarket parts. This all assumes you have engine compression within spec.

My two cents!!

Rick and Lynda Smith
2004 NEWMAR DSDP M-4011-SPTN 8.9 Liter Cummins
2011 GMC SLT 1500 4WD CREW toad
vapor3000 is offline   Reply With Quote

454, chevy

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
Fuse circuits and 12 volt systems test on 83 Pace Arrow Chevy P30 with 454 kartvines Fleetwood Products Owner's Forum 6 01-10-2011 09:37 AM
Downshift TH400 into 2nd for downhill compression braking? Gary - K7GLD Vintage RV's 38 06-21-2010 11:54 AM
1998 Airstream on Chevy chasis /454 Louie De Carolis Class A Motorhome Discussions 8 04-28-2008 07:06 AM
Tuning and timing a 454 Chevy AeroAtom MH-General Discussions & Problems 11 01-07-2008 06:41 PM
86 chevy 454 operating temp chuck7 MH-General Discussions & Problems 5 09-24-2007 06:44 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 11:23 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.