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Tranny in question is out of a 31 foot motorhome powered by a 454. ('85 Holiday Rambler).  It needs a rebuild, but I think it might be a 475 and not the 400 I thought it was.  Vaccuum modulator is on the right side just behind the bellhousing, and the pan looks the same as a 400. After removing the parking brake it is still WAY too heavy for one person to pick up.  I ran a VIN decoder on the vehicle, but tranny wasnt listed.  How do I tell and where do I look for a master rebuild kit?
Thanks in advance...  

How to tell a TH475 from a TH400:

Were installed in light heavy duty trucks and RV's (this one came out of an RV)
more than likely..

6 bolt converter
Factory deep pan
Tailhousing mounted parking brake
Internal: Straight cut planetaries





i could be totally wrong...

and if the transmission has ever been rebuilt.. it may or may NOT still have the straight cut planetaries

the straight cut gets reduce the side loading on the thrust washers..  so the gear train is not trying to spread its self out..

there are also a few transmission rebuilders who know how to convert these to additional roller thrust bearings and needle bearings in some of the bushing locations..   takes a bunch of additional machining to make them work..  when the roller bearing transmissions are sent out on the road.. they last a LONG long time... and take all kinds of abuse..  towing massive trailers.


with straight cut gears the below is not needed.. as the transmission gear train is not trying to expand under load

high HP units with regular gear train, cut the front planet for a t-350 pump torrington bearing between the 2 planets. ALso run a torrrington bearing at the rear of the case with a C6 bushing replacing the OE case t-400 bushing  

Yes this is what I have.  Thank you very much!  Ive heard about the bearing mods, but I dont know if theyre necessary for my application.  It will only be driven 1000 miles a year, if that. I believe the pump failed, as it breifly (10 minutes) made the sound a starving power steering pump makes.  The pan was extremely clean and valve block looked fine. I was hoping the filter fell off or something stupid. No such luck.
Thanks for the input  

Anyone know where to get parts for this?  Id like to do an overhaul, but all im finding on the web is 400 stuff.  

looks like a TH400 rebuild kit will work... except for the output shaft seal..

there are transmission parts suppliers... these are NOT transmission rebuilders.. they sell parts to rebuilders..  some sell nationwide.. some are local.. depending on where you are..

usually there are 3 or 4 transmission professionals to answer questions on transmissions.. i hope i have not made them mad by taking their fun...

someguy .. post kinda where you are located..  just get close..

when i looked it up at autozone.. for a 77 chevy truck C35..454.. they show kits for 80 and 100 bucks.. but you have to call the phone number on the site for the proper kit before ordering..

napa stores as do most other parts stores can order the kits..

you might google.. TH475 parts..  there will be a 8 page parts catalog on the first page..  a great reference..

perhaps some of the transmission guys will post or PM you their favorite   PM is better..  transmission parts suppliers..  they have dealt with...

i have a local guy i deal with .. but he does NOT ship..  he does deliver locally.. to 90019..


looking at the torque converter catalog i have with pictures from transtar..   you seem to have either 2 or 4 choices of six lug converters..   since you are wanting heavy duty.. this reduces it to 2 options..  

Are you sure you don't just have a clogged filter? 400's are notorious for that. If the pan is clean and you haven't pulled the trans i would try a new filter.

400's and 475's are basically the same trans. The overhaul kit is the same for both. Everything is the same . The only difference is the strait cut on the planetary gears.