Picked up a 700R4

[AZ79K5Project]

I scored a 700R4 today at a local yard. I went yesterday for TBI fuel lines and found the 1990 1500 with the drive lines out of the way and transfer case already dropped. I’m swapping a TH350/203 to the 700R4/203. I’ll go through the 203 when I drop it.

The 700R4’s fluid is bright with no burnt smell
The torque converter has a sticker showing 01/2018 for a possible rebuild date. The flywheel looks almost new and not 30 years old. I grabbed that too.

Do I completely change the fluid, filter and gasket and throw it in and try to run it or take it somewhere to be gone through and then install it?

 

[centexk5]

While part of me says just send it, the rational part says have it gone through first. I hate transmissions so the less I have to work or worry about them the better.

 

[Wes Harden]

was there an obvious reason for the truck to be in the yard, other than maybe a bo trans?

 

[AZ79K5Project]

was there an obvious reason for the truck to be in the yard, other than maybe a bo trans?

Good point. The truck was pretty picked through. Interior gone and engine bay picked through. This pull-n-save is pretty busy and they move their stock pretty quickly.

 

[diesel4me]

It appears to have been rebuilt recently and is too clean to be "old"..
Its always a gamble with used automatics,but I've seen worse end up working fine--but on a 700R4 if someone installed it and didn't adjust the TV cable right it could burn it up in a few miles too..

Being frugal,if it were me I'd stick it in and hope its good,its unfortunately the only way to tell..unless you have a grand to spare to get it torn down and inspected & rebuilt..perhaps for nothing..

When I worked in a junkyard we often got a lot of good parts,many new or recently rebuilt things on a vehicle we hauled in--often the owner spent way too much on the vehicle to start with,then when one more thing went bad on it,they got pissed and junked it!..the straw that broke the camels back so to say..

I remember a 350 Chevy engine came in one day in an old rusty truck and it had every external part replaced--new carb,fuel pump,distributor,coil,plug wires--guy who scrapped it said "I give up--I spent $500 on it and it still skips--must have a burnt valve or something--I'm done..

We pulled the valve covers off and found one rocker arm laying in the head ,broken in half,and a bent push rod--the rocker arm stud had a slot cut into it...we pulled the stud out and took one from a junk engine,hammered it in,and used a rocker arm & push rod from the same engine and put it together--it ran perfect!..we used that for our "torch truck" for a long time ..

 

[6872xtc]

I would try it. But you do know that the tailshaft is too long to bolt a 203 up to it , right? If you get one if the 1.75" spacers that was designed for putting a TH350 in where a 700R4 was, and you trim the bevel off of tailshaft, it will bolt up.

 

[AZ79K5Project]

I would try it. But you do know that the tailshaft is too long to bolt a 203 up to it , right? If you get one if the 1.75" spacers that was designed for putting a TH350 in where a 700R4 was, and you trim the bevel off of tailshaft, it will bolt up.

I ordered the spacer from ORD earlier today.

 

[MT Bill]

I'd put it in and run it first. No point in wasting money on a rebuild if it's fine. That's just my thoughts.

 

[AZ79K5Project]

I was kinda thinking nothing to lose by trying it.

 

[Chevy350Ben]

I say send it! just take it easy for a few laps around the block, check for any signs of slippage, odd sounds, shift right etc...

if it aint right, another two hours to take it back out, and your in the same spot. So worst case scenario, you wasted a day. Best case, everything is great and you saved yourself 1000 bucks. The cost/benefit, for me, says to try it first.

 

[ZooMad75]

I'd at least put new seals in it that you can get to easy with it out. Drop the pan and look for debris. If it just has the little bit on the magnet, put a new filter in. Run it.

 

[AZ79K5Project]

I’m definitely going to check the pan for debris and try it. It looked like the build was in January, 2018with a transmission fluid flush recorded in March of 2018 according to Carfax. The vehicle was serviced again in 8/2019 on the same report so I know (presume) the transmission was still running then.

Fingers crossed.

 

[sublimejoker69]

Did it run alright? The suspense is killing me.

 

[AZ79K5Project]

I’m pulling the TH350 out this weekend. The NP203 is a beotch!!! Heavy AF!!! The thing almost killed me.
I want an NP205. I passed up a bunch of local postings over the last year. Now I can’t find one. Oh well...

 

[diesel4me]

When I swapped a NP-205 in a '74 GMC that had a TH350/NP-203,the front drive shaft was too long,I had to search around for one that was about 23" long instead of 27" (roughly)--a friend had a '69 K-10 rotting in his field that had the perfect length front shaft,it was the only year GM used one that length I believe..saved me from having to have my original cut down..the rear driveshaft fit OK though..

If I remember right I had to cut the floor out for the NP-205 shifter,it was mounted to the T-case adapter instead of being a separate unit--my truck had a 2wd cab with a 4x4 tranny hump also,the NP-205 came very close to hitting the floor,but it had 3" body lift blocks so it cleared by about 1"...

 

[AZ79K5Project]

Update - the stock output shaft wouldn’t work - even with the normal mod. I ordered an output shaft from ORD and paid a local shop $200 to swap it out. The guy looked at the transmission while apart and said it was in great shape.

Get it in today with some help from friends and it’s good. I hit the jackpot with this find.

Transmission: $90 + fees
Output shaft and installation : $379 (would have been the same cost for any 700r4 I picked up)

I do have to get new driveshafts now. The front is too short with the lift and the 1.75” difference in drivetrain length increase and the rear is too now long - won’t collapse enough to drop it in.

 

[imiceman44]

Update - the stock output shaft wouldn’t work - even with the normal mod. I ordered an output shaft from ORD and paid a local shop $200 to swap it out. The guy looked at the transmission while apart and said it was in great shape.

Get it in today with some help from friends and it’s good. I hit the jackpot with this find.

Transmission: $90 + fees
Output shaft and installation : $379 (would have been the same cost for any 700r4 I picked up)

I do have to get new driveshafts now. The front is too short with the lift and the 1.75” difference in drivetrain length increase and the rear is too now long - won’t collapse enough to drop it in.
View attachment 360936

Man I wish I saw this before.
I went through this already and I bought 2 sets of spacers, one used without studs then one new with studs, and realized that the extra length was going to be a problem since I had a doubler, so I paid to get the short shaft put in and while in there fixed a few issues with the trans.
I still have the spacers, the new one still in the packaging.