What tranny do I have??

[jeff in co]

89' k5 blazer.

OK suppose to be 700R but who knows what's been done in 300k. So, I originally thought they just switched out the whole steering shaft because the old one was worn out but then I got to thinking that maybe they switched the transmission and had to get a different steering column??!! I just don't know.

I found a section actually in the LMC that said if I had a square pan and 16 bolts, it is indeed the 700R. However, when I shift into "OD".....I only have two more lower gears which makes me think maybe a 350 tranny. It says "MD8" on the side in large letters.

If I have the 700R, why don't I have one more gear? Or did they do something goofy when installing everything? Just trying to get an idea on this truck! Did have some success this weekend and put in a new radiator (all metal) and it's running much better! Still, a work in progress.

Here are some pics of the tranny.

 

[Muddytazz]

Hopefully this will help you out.


http://www.nastyz28.com/chevy-transmission-identification.php

 

[jeff in co]

Hopefully this will help you out.


http://www.nastyz28.com/chevy-transmission-identification.php

That does help, thanks. So, according to the "MD8" I must have the 700R4 but what I don't understand is the shifting on the column. I only have "3 forward gears" instead of the typical "OD D 2 1". Would it be because of the new steering column not allowing this next position or did they install it wrong somehow?

With 37" tires at about 65 or 70 mph the rpms was around 2000. Of course, I still don't know the axle ratio yet.

 

[USSkoval]

I'd guess the steering column is not allowing you to access 1st gear.

 

[POORBOYK5]

the linkage could be out of adjustment too. I'm not too sure on the column differences.

 

[jeff in co]

the linkage could be out of adjustment too. I'm not too sure on the column differences.

This does make a little more sense. I do have to wiggle it around ever so slightly to get it into "drive" and when I put it into park, I need to shove it with just a tad bit more effort to get it all the way locked into park. I appreciate the help.

I did jack up the rear end and counted the drive shaft rotation to be 1-7/8 per one wheel rotation. Other wheel was spinning in opposite direction so I figure, open diff. Doubling this rotation brings me to 3:73's on 37" tires. Which make sense because I switched them out LONG ago from 3:42's.

Also, can't believe we got the truck into the garage! Made it with about 1/2" to 3/4" clearance! Unbelievable......

 

[4X4HIGH]

That is a 700R4 for sure. If your steering column doesn't have P R N OD D 2 1 then the indicator is the wrong one (most probable because someone changed the steering column as you've said). There is no difference between columns (just the indicator). You need to find a OD indicator and install it then adjust the linkage so that you get all gears.

 

[jeff in co]

That is a 700R4 for sure. If your steering column doesn't have P R N OD D 2 1 then the indicator is the wrong one (most probable because someone changed the steering column as you've said). There is no difference between columns (just the indicator). You need to find a OD indicator and install it then adjust the linkage so that you get all gears.

They actually left the indicator....just broke the string on the column. Also, there is a loose piece on the column that I'll need to re-attach. I'm actually glad it's the 700R4. I felt like it was shifting through all those gears but not allowing me to manually shift down gave me question. I was almost heading the the junk yard to pick up a D 2 1 pattern.....but now I'm good. I might just pick up a replacement one that doesn't have the string broken. May be easier anyways.

How would I adjust the linkage? Is this a tough deal or should I just bring it into a tranny place?

Thanks for all the help again.

 

[4X4HIGH]

To adjust the linkage you need to first block the wheels so the rig can't move. Now you need to get under the hood and loosen the adjusting bolt on the linkage from the column that goes down to the trans, now manually shift the trans into park and the column shifter into park (might want to have someone hold this in park for you), now tighten the adjustment bolt and you're done.

 

[jeff in co]

To adjust the linkage you need to first block the wheels so the rig can't move. Now you need to get under the hood and loosen the adjusting bolt on the linkage from the column that goes down to the trans, now manually shift the trans into park and the column shifter into park (might want to have someone hold this in park for you), now tighten the adjustment bolt and you're done.

Cool, I'll give it a shot. Thanks!