Author Topic: TH400 not shifting till 4,000 rpm  (Read 15168 times)

Offline Dr_Snooz

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Re: TH400 not shifting till 4,000 rpm
« Reply #15 on: January 19, 2011, 10:38:08 PM »
I'm glad I asked, because I could have searched for a million years and never realized that it goes here:



I'm not sure how you guys are putting these valve bodies back in, but I had really good luck greasing the checkballs slightly like so:



The grease really held well. I tilted and bumped the valve body as I was lifting it and they stayed put through it all.

I had this spare bracket lying around, so I held the front servo piston in like so while I bolted the valve body.



I also took the opportunity to replace all the little case seals (selector shaft, governor, speedo gear, kickdown switch, etc). I got all of them but the tailshaft seal and the front and rear seals. When I drop the driveline some day, I'll get the tailshaft and rear seal.

The good news is that the truck is running again!!!! Hooray!!

Thank you all for your help!
« Last Edit: January 19, 2011, 10:42:09 PM by Dr_Snooz »
1989 Chevy Suburban V-2500, 5.7L, TH400

1990 Chevy C-3500 Ext. Cab, 7.4L, 3L80

2009 Chevy Silverado 1500 WT 4WD, 4.8L, 4L60

Offline VileZambonie

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Re: TH400 not shifting till 4,000 rpm
« Reply #16 on: January 22, 2011, 08:45:19 AM »
FYI

Grease is NOT what you want to use in an automatic transmission. Vaseline/petroleum Jelly or trans gel.
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline Jim Rockford

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Re: TH400 not shifting till 4,000 rpm
« Reply #17 on: January 22, 2011, 02:12:40 PM »
If that is Lubra-plate engine assy lube  He would be fine with just that little bit.
1973 k20 Camper special
1980 k20 custom deluxe
2004 Crown Vic LX sport

Offline VileZambonie

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Re: TH400 not shifting till 4,000 rpm
« Reply #18 on: January 23, 2011, 10:41:10 AM »
Using white grease is not an acceptable practice in assembly of automatic transmissions. You need a petroleum based low melting point lube like petroleum jelly or transjel.
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline Dr_Snooz

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Re: TH400 not shifting till 4,000 rpm
« Reply #19 on: January 24, 2011, 11:16:42 AM »
Oh. Good to know. Anyway, the truck passed smog today. It's running great.

Thanks again for all the help.
1989 Chevy Suburban V-2500, 5.7L, TH400

1990 Chevy C-3500 Ext. Cab, 7.4L, 3L80

2009 Chevy Silverado 1500 WT 4WD, 4.8L, 4L60