My-6 new process 3-speed overdrive

[siataspring850]

I have a 1987 step side 4.3 with the new process 3-spd o.d. I read on this site that in 1987 Hurst sold to Mr Gasket so only 300 trucks were sold with this set up. I am pulling the tranny soon and swapping it out with a Saginaw 3 spd. The MY-6 sounds like it has the input.. bearing going bad
My question is since only 300 were made and 87 being the last year should I rebuild the old tranny and keep it stock? Also does anyone know if the drive shaft will match up? I cant get under the truck until next week and if I need to change on the drive shaft I'll have to get one before I do thew swap

 

[squaredeal91]

Wouldn't be a bad idea to rebuild. You definitely have a Gem. If anything keep the original around

 

[Keith Seymore]

I read on this site that in 1987 Hurst sold to Mr Gasket so only 300 trucks were sold with this set up.

Not quite what I said;

I said that 100 were built under the Temporary Deviation (one of which happened to be mine).

I don't know if they went back and opened up the production volume if/when the supplier issue was resolved.

K

 

[Keith Seymore]

and 87 being the last year

Not sure about this, either.

Since the MY6 trans was also available in the full size Blazer it conceivably could have been had in the '88 and '89 V Blazer models.

Unfortunately those generic info packets are not in the GM Heritage Center archive so I can't verify.

I can say the '90 and '91 V Blazer info packets are in the archive and the MY6 trans is not specifically shown as available.

K

 

[Keith Seymore]

should I rebuild the old tranny and keep it stock?

Yes - I would keep the MY6.

It's a cool little trans, plus you get the bragging rights of having a MOPAR trans (and the cool Hurst shifter) in your truck from the factory.

And - it is admittedly rare-ish across all the model years, regardless of if the number is 100 or 300 or 10,000.

Did I read somewhere you have a 3.08 rear axle? That's probably what is killing your off the line performance/launchability.

I would recommend a 3.73 rear axle ratio, which will really help off the line and with the overdrive it brings you back to (an effective) 3.42 ratio going down the road.

K

 

[Keith Seymore]

The MY-6 sounds like it has the input.. bearing going bad

This could be the clutch throwout bearing - which would be bad regardless of the trans used.

K

 

[siataspring850]

Thank you for all of your replies. I think it is a great truck. I am going to pull the tranny and see what is up with it. If it is a throw out bearing I'll be lucky. Normally I could feel the throw out bearing through the clutch peddle. But I might have lost that skill set. They shouldn't be hard to rebuild I've rebuilt top loaders many many years ago.
Some times I just have to reach out and get a feel for what others think and know. I am going to pull the tranny and see what is up with it. I will let you know how it turns out
The value of the truck is I like
Thank you all again

 

[Ricko1966]

Drive shaft will work,bellhousing probably will not. Make sure your bellhousing has a bolt pattern for your new transmission.

 

[siataspring850]

Thank you for the information. The drive shaft was a big concern. I wont move it into the in a real garage to look it over for a few more days I thought I got lucky buying the 3 speed it came with the bell housing out of 85 C10 should be a easy swap out. Then I can look into the MY-6. I rebuilt it one year's ago. I could get lucky again and the noise is the throw out bearing or the wrong fluid? I think they used Ford ATF fluid.I will let you know how it goes

 

[Keith Seymore]

Correct - MY6 uses ATF.

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K

 

[donnieray]

I'll add a little here, parts are available for the transmission, the shifter is the hen's tooth. The Hurst Comp Plus shifter for the Mopar NP833 will not work on the Chevy since it's an overdrive unit. I found a rebuilt unit at Shifter Doc.com and snapped it up as it was the only one I had seen after three years of searching. As rare as the My6 is, the shifter is far rarer.

 

[RetroC10Sport]

Not sure about this, either.

Since the MY6 trans was also available in the full size Blazer it conceivably could have been had in the '88 and '89 V Blazer models.

Unfortunately those generic info packets are not in the GM Heritage Center archive so I can't verify.

I can say the '90 and '91 V Blazer info packets are in the archive and the MY6 trans is not specifically shown as available.

K

The trans is so rare that if one went to a junkyard looking for it, they would be told it doesn't exist as it's not in the Hollander interchange. Though, obviously they DO exist.

 

[donnieray]

The trans is so rare that if one went to a junkyard looking for it, they would be told it doesn't exist as it's not in the Hollander interchange. Though, obviously they DO exist.

You are very correct, my search for a shifter got me some blank stares.

 

[RetroC10Sport]

You are very correct, my search for a shifter got me some blank stares.

I'll have a look through my accounts, I haven't inventoried an MY6 truck but I will see if someone might have one in their inventory - assuming it's been entered correctly and it's not an SM465 truck.

 

[RetroC10Sport]

You are very correct, my search for a shifter got me some blank stares.

Maybe try S & J Motor Company, Inc. in Yadkinville, NC 336-961-2228 No guarantee it's the NP trans and not a Muncie but give it a shot.