Oh boy...Yet another 700R4 swap thread

[Asmoday]

Hello All,

Ok...after many hours of reading different posts on swapping a 700R4 into the M1009 I have just a few specific questions relative to my situation.

I currently own a 1987 K5 gaser with the factory 700R4/NP208 in it. I was already planning on swapping parts from it onto my M1009. I find myself wanting an overdrive gear more and more on the freeways here in SoCal because people are running my a** over...

I'm aware that I will need the specific TV cable, Diesel specific TV Bracket(anyone have one?), flywheel, governor and diesel torque converter and do the lock up mod(hydraulic or electric) for the swap.

What I would like to know is...

1. Can I pull the gaser trans and transfer case out as a unit and drop it right into the M1009 with no other mods other than what's known above?

2. Will I need to move the cross-member and should I use the gaser cross-member or does it not make a difference?

3. I believe that the stock M1009 drive shafts should fit ...correct?

4. I have read that some years of the 700R4 were problematic and had weakness issues with the more desirable units being built from '87 on. Better valve bodies, etc. Is this correct? I have a later in the year build '87 700R4 so I hope this is true...

5. What is the difference between the earlier and later 700R4's?

6. It seems that the spline count on the 87 700R4 is 30. Correct?

I know that I will have to have the 700R4 gone through anyway as it has been occasionally slipping for years in the gaser but I think if it will swap into my M1009 without much work it's a less expensive way to go than a GV unit?

Are there s certain upgrades that should definitely be thrown in on the rebuild?

All answers and opinions are much appreciated...!

Thanks!
Adam

 

[cliffyp]

I just swapped one into my 1028 in the last month. The items that need to be changed; torque converter, governor, flex plate, can all be done without opening up the trans. If you need to change or add lockup, that is just a pan drop. I didn't need to change anything with my crossmember or drive shafts.

Everybody says you need/want to build up a 700r4 to go behind a 6.2, but it was a stock option on many GM trucks so I don't know what that means.

The TV bracket is the hard part to find and also very necessary. Start looking for one.

If its already slipping seems like you might as well rebuild it while its out. If you're going to rebuild it might as well throw in some beef up clutches.

I would be concerned about overdrive with 3.08 gears in the '09. I think it's going to feel sluggish when you hit hills on the highway and want to drop back into 3rd.

 

[cliffyp]

On the crossmember, there are two different adapters for the 700r4/np208, a tall and a short. Using the tall adapter in my 1028 required no mods to my existing crossmember. The short adapter would have required a different crossmember or some other fab work. I don't know what the M1009's have. I pulled the adapter I used from a gasser blazer whose crossmember dropped down below level bottom of the truck. This fit my 1028's straight crossmember that sits level to bottom of truck.

 

[Asmoday]

Thank you for the info...

I will be taking the M1009 off road extensively so I'm hoping my '87 700R4 is one of the "desirable" units.

I don't mind spending a little to get it up to HD spec.

OK...the TV Bracket search begins...I'll keep me fingers crossed.

I know ODw/envy may be getting some made. Hopefully not a long time delay and it will happen...

 

[Recovry4x4]

If there are U pull it yards in the area, start walking them weekly. I have found 2 this way and on the cheap. Don't forget to check the vans.

 

[Asmoday]

Ya...I already checked the yards in my area for a while. Diesels are slim pickings.

 

[SouthernSteel]

Asmoday,here ya go this is all you my friend.http://www.steelsoldiers.com/engine...tion-6-2l-700r4-tv-brackets-interested.html:D These guys might have one they would sell.

 

[Asmoday]

LOL...I already posted on that thread....

 

[SouthernSteel]

LOL...I already posted on that thread....

Lol,I hear ya, Just lookin out for ya.Those brackets are gold the last one i saw for sale on fleabay was listed $125.

 

[klmartin62]

You will need the drain hole drilled out larger behind front seal, and a keeper installed on the seal, if this hasn't already been done. A new pump bushing is always a good idea, and a good quality external cooler.

From '90 to '93 I was the trans guy in a large GM dealership. Most of the above were campaigns to solve problems with the 700r4. I have been away from trans work for over 10 years, but those are the ones I remember. I rebuilt hundreds of them. Temperature is your main enemy. Keep it cool, it will last. 3-4 rapid shift creates tons of heat because convertor cannot lock. On hills pull into 3rd, also when towing. If you forget these rules, you will be walking. These are very unforgiving transmissions.

Good luck.

 

[Recovry4x4]

Older stuff in the U pick yards here turn over quite fast. My success was from going weekly. Each of the 3 times I got one, the vehicile was gone within a week or two. Most folks looking for these overlook vans as well. There were more diesel vans than you would normally think. In the course of buying other more known parts, the cashiers on each case didn't charge me for the bracket.

 

[Asmoday]

So I decided to get under the Civy K5 today and verify my trans specs. It's definitely a 1987 700R4. The code is 7TXM205B which equates to 1987 built on the 205th day of the year. M stands for 700R4. It has the "MD8" and a thin "K" cast on the bell housing so it looks like I have a good trans to start with.

I looked real close at the cross member and it's completely different on the Civy versus the M1009. Mainly because the transfer case adapter is long on the TH400/NP208 combo and short on the later 700R4/NP208. There is a longer adapter that was used on the 82-84 Civys that looks very close to the M1009's length so I will probably pic one up.

I like the idea of keeping the M1009 stock cross member since I have a couple of them as spares.