1986 transmission type

[SkidRo]

I have a 1986 C10 Scottsdale longbed with the original automatic transmission and A/C (if that matters). The transmission has three forward drive (low, second, and drive I believe) positions and Overdrive.  I was told this was a TH350 but a mechanic said it was a 700r4. The mechanic did not look at it.  I need to replace the transmission lines due to rust and leakage.  Basically I want to buy the replacement lines or replace the bad sections with an alternate solution.  Going the full replacement of the steel lines I need to confirm the trans type.  Any help in identifying it is appreciated.
SkidRo

[SkidRo]

A little search resulted in finding the Pan Identification guide within the forum.  I will compare the chart to my transmission pan and then order the lines.  Any recommendations on a source for the lines? However they are $54.95 (which I am fine with) but has a $33 shipping fee due to "over sized".  That is stupid. I received two 8' pieces of wood trim the other day in a  9' long 6" round tube.  Shipping was less than $10.00.

[csdineley]

if it the stock transmission and has overdrive then its a 700r4 and not a th350

[mcintyrederek]

This might be a little more effort than you want to get into... but...

I had nasty lines on my '86 with a TH400.  My fittings were what I call "reverse flare" which may not be the proper term, but the tube ends on the trans. and the radiator were flared like a normal fitting but has a nut behind it which screws into the threads.

I replaced my lines with 3/8" soft copper, reused the fittings and did my own flares with a flaring tool.  Has been working great for several years.  Then again I'm working on a rat-rod, and if you're interested in making yours "correct," then you'll need the right stuff.

External transmission cooler kits come with 3/8" ID hose that resembles fuel line.  There's not much pressure on the cooling lines.

I have seen transmission lines on square bodies in the salvage yard that were all aluminum.  That might also be worth the time trying to find.

Good luck.

[SkidRo]

Thanks for the replies.  I haven't crawled under the truck to check out the pan configuration yet.  It's on the list for tonight. I did see the PO "fixed" the lines with rubber tubing and hose clamps. It looks like he replaced about 2' on each line about halfway back.  It looks like it is leaking out of one of the clamps. From that point forward the lines are rusted until they bend up as they make their way to the radiator.  I could just tighten the clamps but with all the rust this is something that I don't have to worry about when I am rolling around the beltway. 

[SkidRo]

I checked the transmission pan last night.  It is square in shape and maybe 12"x12" with 16 bolts just like #6 below.  I believe that it is the 700r4 so I am going to order the lines for that transmission.  I found that image on http://www.layitlow.com/forums/22-maintenance-repair/246653-thm200-4r-rebuild.html

1 Aluminum Powerglide 14 bolts
2 TH200 Metric 11 bolts
3 TH350 13 bolts
4 TH400 13 bolts
5 TH200-4R 16 bolts
6 TH700-R4, 4L60, 4L60E 16 bolts
7 4L80E 17 bolts

[SkidRo]

I have the new lines.  Does anyone have any suggestions on how to get the new lines installed?  The old lines were rusted in half so it was easy to remove the.  However, the new lines are not really conducive to just sticking them in place and tightening the ends.  They are long and have multiple bends.  What needs to be removed at minimum to get the new lines in?  It looks like I need to drop the exhaust.  What else?  Thanks