TH700R from a 89 K5 Blazer

[stationjj]

I wanted to ask for some advice. I try and look for civvy K5s being parted out. For a few months now I have been considering and looking for a Th700r4 (4L60) core from a 4X4 for future project. My thoughts I could use in my current M1009 if needed or future M1008. I do realize I will need to make mods to tranny for use on M1009 or M1008, and find a TV cable bracket.

I found a 89 K5 4x4, 350 V8 being parted out. This model has the Th700r4 Tranny. From research I have done this tranny could fit a M1009 or M1008 with mods made? It's from a 4x4 and right time period. I don't think it is the electronic one 4L60E that came out in the early 90s.

The tranny has been pulled and ready to load and go. Should I get the transfer case as well? What's a fair price for a th700r4 core?

I am new to transmissions and such. I wanted to verify it could be used for future projects?

Thanks for your input.

stationjj

 

[Warthog]

That tranny will be a good canidate. $100-$125 are the going rates for a core here in Oklahoma. Grab the transfer case if the cost isn't too high. It will save you some $$ when you are ready to do your conversion

 

[Recovry4x4]

That's a great candidate. The transfer case should be an NP241C. Check the tag on it and make certain that the output side has provisions for a speedo cable. If you choose to re-use your NP208 it will need the input gear changed to a 27 spline from the current 32 spline. The 241 gear is different I am told. The tranny will need a governor change and as mentioned the TV cable and bracket. Torque converter also needs to be changed. You will also require a new flexplate for your 6.2. Speddmon just did a similar swap and documented it pretty well.

 

[stationjj]

Warthog,

Thanks You for the confirmation! I thought it would work. I wanted to verify.

I am trying to plan ahead. Hoping when the time comes the cost won't hit me so hard. The right 700r4 for the cucvs will only get harder to find.

Thanks,

stationjj

 

[Speddmon]

I don't think that R4 cores will dry up any time soon. Pretty much any R4 with a "k" case from a full size 4x4 (probably '90 and older) will work. Unless you happen to find one that was mounted behind a 6.2 from the factory all of them are going to need the mods Recovry4x4 mentioned.

 

[Warthog]

Around here in OK, almost all the salvage yards are crushing anything older than the mid '90s. So, while GM made millions of the trucks, the 4x4 versions are getting harder to find.

YMMV

 

[cliffyp]

Cores through 1992 will work and some 93's. They switched to electronic controlled during '93. I agree with Warthog, because the 700's have been so plentiful people have regarded them as throw away, and many have been. I think we are approaching a time when people will reminisce about the times that you could kick a rock and find a 700 being almost given away.

 

[stationjj]

I agree with Warthog from what I found out here in TN. The salvage yards I have checked you can sometimes find a late 80s or early 90s Blazer, Suburban, and truck. They are becoming harder to find. Yes, I can find a tH700r4 in my area, but one that is from a 4x4 and right time period NO. A local salvage owner told me he hasn't had a 80's 4x4 th700r4 tranny in quite a while.

That's my reason for buying it. The supply is drying up. The last ones that will work with the CUCVs were made 20 years ago.

My Thoughts

stationjj

 

[sierrajcharlie]

Just curious Speddmon, do you think the swap was worth it? Been reading on here on it and the opinions vary. I have an 86 civvy K5 with one that's sitting behind a 6.2. The tranny, transfer case and front end are the only things left worth a hoot in it. To get it out of the yard it may be going to the shredder. Thinking about pulling the tranny and case but trying to decide if its worth the effort. Thanks!

 

[Warthog]

If you don't want it, I'll take it.

 

[stationjj]

sierrajcharlie

A 6.2 diesel tranny? I would love the TV Cable bracket!

Warthog, you can everything else. I need a good tv cable bracket.

If you want to part out? Please send me a PM!

stationjj

 

[sierrajcharlie]

Wow! Apparently I have something harder to come by than what I realized! I appreciate the input, it will not be going to the shredder and be going into this one next spring. I've got a leak in my transfer case now that my son says he'll look at in the next couple of weeks. Hopefully it's an easy fix or maybe the swap may be needed sooner!

 

[cliffyp]

In my opinion, swapping a 700 into any of the CUCV trucks with 4.56 gears is very worth it if you want a highway driver. It is not a difficult swap. I did all the work myself, including building the tranny, and I have no experience working on vehicles. I enjoy driving my 1028 so much more now and have been using it as a DD because of this.

 

[Speddmon]

Was it worth it?...YES!!!

The truck drives more like a civi vehicle now. It's way easier on the highway now, and much quieter. Personally, I wouldn't waste my time doing it on a 1009, but any of the ones with the 4.56 gearing it is a must have. As was mentioned, the work is not bad to do, it's actually pretty straight foreward.

 

[wayne pick]

As 700R4 swaps for M1009s seem to be the trend lately, Has anyone considered a TH350 with a lockup converter? It may be a better fit for the 3.08 gearing in the 09. A TH350 in lockup will drop approx 500 RPM off the engine making it basicly a three and a half speed trans. The TH350 can be built far stronger than a 700R4. The HD 4x4 long output shaft version would have to be used along with a 27 spline NP208 TC, or the short shaft version for an NP205 TC. Most 350s had the NP205 behind them anyway. No TV cable bracket or adjustments needed either. Any thoughts?

 

[stationjj]

Thanks everyone for your input, and help.

Today I went and recovered a Tranny and TC from a 89 4x4 K5 Blazer. My plans are to put her in a future M1028.

Pictures Below;

 

[Speddmon]

Good job. If the tranny and transfer were good, you might as well save the torque converter as well. While you can get a 1600 stall converter easy enough...you already have one, might as well save it.

 

[cliffyp]

Check the adapter between the two, you'll need the tall adapter to fit the stock crossmember in the 1028. Speaking of, I have a short adapter for 700r4/np208 if anyone needs one.

 

[Speddmon]

You can use the short adapter. all you need to do is fabricate a little 3 1/2" riser to bolt between the adapter and the cross member. It's actually a very simple thing to make. I used 3 pieces of 1" key stock and a piece of 1/2" x 1" flat bar to build mine up. Drill and tap two 1/2"-13 holes about 6" apart center to center at the bottom, and drill 2 holes about 27/64" or 7/16" diameter, about 7 17/32" apart center to center on the top. easy!

 

[cliffyp]

You can use the short adapter. all you need to do is fabricate a little 3 1/2" riser to bolt between the adapter and the cross member. It's actually a very simple thing to make. I used 3 pieces of 1" key stock and a piece of 1/2" x 1" flat bar to build mine up. Drill and tap two 1/2"-13 holes about 6" apart center to center at the bottom, and drill 2 holes about 27/64" or 7/16" diameter, about 7 17/32" apart center to center on the top. easy!

Oh!!! That's what I did wrong.

I pulled my tall adapter from a K5 in a junk yard (year unknown), so you may be good to go already.