Any transmission guys here ?

[greenjk]

Hi to anyone that may be able to help, I have a 83 Suburban 350 t700, trans was rebuilt 8 years ago and has only done 50,000kms (around 30,000m) did a trip last weekend to a hot rod show about 4 hours drive from home no problems on they way there or for the next 3 days, driving home on Sunday mostly highway running and temps around 25-30 c (75-85 f) going up a slight hill with light throttle doing 110kph (65-70mph) the trans slipped in OD, I backed off and slipping seemed to stop.Noticed a bit later it was doing it again so I pulled over when I could and checked the trans fluid, having to add around .5 of a litter (almost a pint) by this time it was slipping worse in 3rd and 4th so I slowed down and drove in 2 trying to make it to next town, soon after it lost all drive including r and had to come home on flatbed, any Idea what the problem may be, I know it's a long shot but not many people know a lot about these transmissions over here.

[old man 52]

With all the gears being gone it sound like it could be a torque converter , Pull the pan and see how much band material is laying in the bottom.

[greenjk]

Thanks mate, just got it up in the air and about to pull the pan.

[old man 52]

I just talked to a buddy of mine and he's said it could also be the pump.

[greenjk]

Thanks mate, got the pan off and there are some fine particles in the bottom of the pan and stuck to the magnet but nothing else.

[old man 52]

So whats the verdict , Any updates.

[taco08jk]

700r4 you mean? First I would do a pump test. A shade tree mechanic way of doing a pump test is to get under the truck and disconnect the output line and while your under the truck have someone crank the truck, if you see fluid coming out of the output then your pump is working. ( DONT LET IT RUN TO LONG) you should see fluid within 5 to 7 seconds.


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[taco08jk]

Also, you need to make absolutely sure your tv cable is adjusted properly. If it's off by just a lil bit it will cause low line pressure which will result in soft clutch pack engagement and cause them to slip and possibly burn up.


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[greenjk]

Originally Posted by old man 52

So whats the verdict , Any updates.

Not yet mate, I got the pan off and don't see anything unusual, a little bit of metal on the magnets but probably no more than I would expect after the kms it's done.

[QUOTE=taco08jk;4950946]700r4 you mean? First I would do a pump test. A shade tree mechanic way of doing a pump test is to get under the truck and disconnect the output line and while your under the truck have someone crank the truck, if you see fluid coming out of the output then your pump is working. ( DONT LET IT RUN TO LONG) you should see fluid within 5 to 7 seconds.

Yeh mate, 700r4 down here there commonly called a t700 I'm waiting on a filter and a pan gasket then I'll refill it and give the pump test a go.


[QUOTE=taco08jk;4950949]Also, you need to make absolutely sure your tv cable is adjusted properly. If it's off by just a lil bit it will cause low line pressure which will result in soft clutch pack engagement and cause them to slip and possibly burn up.

I was also going to check the tv cable and will do that after I check the pump. Thanks for the suggestions.

[taco08jk]

Any updates?

[greenjk]

Not yet mate, I'm still waiting on the filter and gasket. Do you know much about these autos, If I haven't killed it is there things I should look at upgrading.

[taco08jk]

No I don't have much experience with it, I just know the basics. I do know that when GM switched to the 700r4 overdrive tranny from the TH400 4speed auto they gave up durability. The 400 was way stronger than the 700r4.


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[Bronco39]

Here's a 2nd vote for making sure the TV cable is properly adjusted