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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: mtjd25 on February 28, 2011, 11:28:53 am

Title: Th 400 overdrive, 77 p30 chassis....thoughts?
Post by: mtjd25 on February 28, 2011, 11:28:53 am
Hey guys, I just bought a 77 southwind motorhome, its on a p chassis, I bought it for the 454. This has a th400 with an eaton overdrive bolted to the back of it. It looks very factory. Couple questions. Is it factory, and are they common.  Any information you might have is greatly appreciated.

Matt
Title: Re: Th 400 overdrive, 77 p30 chassis....thoughts?
Post by: Captkaos on February 28, 2011, 01:07:25 pm
What kind of Eaton?  got pics?  Never heard of it.
Title: Re: Th 400 overdrive, 77 p30 chassis....thoughts?
Post by: mtjd25 on February 28, 2011, 02:54:11 pm
I do not have any yet, we removed the drivetrain yesterday, and it was a suprise to me to see it there. I am at school, but will snap a couple pics as soon as i get home this week and post them. there is the possiblity it was an aftermarket add on, but I'm doubting this just by how everything looks on it. It bolts on to the tail shaft, like any other overdrive or a t-case would.
Title: Re: Th 400 overdrive, 77 p30 chassis....thoughts?
Post by: zieg85 on February 28, 2011, 04:26:25 pm
It is an aftermarket add like gear vendors did back then.  They took the rear tailshaft off and had an adapter for whatever trans it was going to be mated too.  I would like to see a picture as well, have only seen one from underneath
Title: Re: Th 400 overdrive, 77 p30 chassis....thoughts?
Post by: mtjd25 on March 07, 2011, 12:25:27 pm
As requested here are the pics of the overdrive I removed. Let me know anything you guys know about it. Sorry it took so long, but I am a full time college student; got home, and internet has been down. So now im back at school posting.
(http://i574.photobucket.com/albums/ss181/mtjd252009/od2.jpg)
(http://i574.photobucket.com/albums/ss181/mtjd252009/od.jpg)
Pre Tear down of the southwind, the 88 ready to load.
(http://i574.photobucket.com/albums/ss181/mtjd252009/aca.jpg)
Tear down
(http://i574.photobucket.com/albums/ss181/mtjd252009/camp.jpg)
and here is what my truck looked like after towing it home down the road from a neighbors house...The camper was sunk in the ground pretty good, and my yard was a mess, so...so much for having a clean truck.
(http://i574.photobucket.com/albums/ss181/mtjd252009/184672_1587744816743_1329480060_31281790_325638_n.jpg)
Title: Re: Th 400 overdrive, 77 p30 chassis....thoughts?
Post by: billywilly92 on April 01, 2011, 04:12:21 pm
Any ideas on this yet? It looks like it could have a pto added on the side.
Title: Re: Th 400 overdrive, 77 p30 chassis....thoughts?
Post by: VileZambonie on April 01, 2011, 09:29:13 pm
Unless one of these falls into your lap an O/D unit isn't worth it. You can build a 4L80E for much less $ and less weight. Many motorhomes came with overdrive units.
Title: Re: Th 400 overdrive, 77 p30 chassis....thoughts?
Post by: Blazin on April 02, 2011, 02:14:27 am
I have seen several types of over drive units in older motor homes. I don't know for sure but I always thought they were something the coach company added after they took delivery of the chassis.
Title: Re: Th 400 overdrive, 77 p30 chassis....thoughts?
Post by: 79chevykid on April 02, 2011, 06:21:56 pm
Could it be a th475 with a transbrake? Iv heard of them in motorhomes but never seen one so idk what it would look like
Title: Re: Th 400 overdrive, 77 p30 chassis....thoughts?
Post by: zieg85 on April 02, 2011, 06:36:39 pm
Wish I would have never traded my Gear Vendors unit now that I have that 4.56 gear out back of my C30...
Title: Re: Th 400 overdrive, 77 p30 chassis....thoughts?
Post by: Blazin on April 02, 2011, 10:47:08 pm
It could be a TH475, but a trans brake is internal.
If your talking about a TH475 with a out put shaft emergency brake it would have the brake drum behind the overdrive unit on this particular one.
Title: Re: Th 400 overdrive, 77 p30 chassis....thoughts?
Post by: DnStClr on April 04, 2011, 07:40:13 pm
Zeig's right- Here's a closeup pic of a gearvendors unit- they cost @ $3500.  :o

(http://i227.photobucket.com/albums/dd22/Dnstclr/GearvendorsOverdrive.jpg)