1985 CUCV M1009: Best replacement transmission

[rhinob]

Greetings,

I'm soliciting any and all suggestions for what you'd replace a stock transmission in a M1009 with.

Thanks much,

Den

PS - My trans is fine - Just thinking of a better suited trans for highway, etc.

 

[GunnyM1009]

Most everyone goes with the 700r I believe. Mine went out over the weekend and I believe thats what I am going to do.

 

[richingalveston]

most go with the 700r4 due to the no electronics. what you end up with instead of a computer, you have a TV throttle cable that can easily toast your tranny if it gets messed up.

The cost between the 700r4 and 4l80e are about the same except for the computer which is $600.

The 4l80e is a heavy duty tranny the 700r4 can be built to be heavy duty but doing that can add more to the cost than the 4l80e computer.

It is your call. The overdrive tranny's only lower your rpms at highway speeds, they can help because of lower first gear. But they do not improve fuel mileage. the mileage can actually go down because you are using the motor at a lower rpm and thus lower horsepower.
The 700r4 will be ok in a blazer but I would not put it in a truck where I would be towing heavy loads. I would not tow any significant loads with a blazer.
just my two cents. I went with the 4l80e and love it.

 

[GunnyM1009]

most go with the 700r4 due to the no electronics. what you end up with instead of a computer, you have a TV throttle cable that can easily toast your tranny if it gets messed up.

The cost between the 700r4 and 4l80e are about the same except for the computer which is $600.

The 4l80e is a heavy duty tranny the 700r4 can be built to be heavy duty but doing that can add more to the cost than the 4l80e computer.

It is your call. The overdrive tranny's only lower your rpms at highway speeds, they can help because of lower first gear. But they do not improve fuel mileage. the mileage can actually go down because you are using the motor at a lower rpm and thus lower horsepower.
The 700r4 will be ok in a blazer but I would not put it in a truck where I would be towing heavy loads. I would not tow any significant loads with a blazer.
just my two cents. I went with the 4l80e and love it.

Does the 4l80e bolt right up and what all is there to installing the standalone trans controller. I do plan on pulling a 28ft bumper pull camper from time to time so it may be worth doing the 4l80e if there isnt a whole lot to making it work.

 

[patracy]

The M1009 has 3.08 gears in the axles, has your gears or axles been swapped? I ask this because at 70mph you're only turning about 2500rpm.

 

[richingalveston]

to much trailer for a blazer.

I have 4:56 gears but 39 inch tires so it is like having 3:08
you are better off with th4oo and good trans cooler if you want to pull that much behind a 6.2
you will never use 4th with the load anyway.

 

[GunnyM1009]

No gears have been swapped yet. I was thinking about going up to 4.10 before I start pulling the trailer though. Or possibly finding a 14 bolt rear. I only run 33x12.50 R15 on Gunny though

 

[NovacaineFix]

It's really a matter of what you are doing with the truck vs. what you feel comfortable paying to mod it out and how far you want to go.

The TH400 is a pretty strong and very reliable trans even in stock form, but sadly missing a 4th gear. You can keep the TH400 and go with a Gear Vendors unit, but that will set you back about $3K from what I estimate.

The TH700R4 is a standard level transmission that can be built up, but to make it as semi-reliable as a TH400, you're probably looking at $2200 - $2700 depending on how far you go. In my opinion, the 700R4 will never be as strong as a 400.

You can go the 4L80E, which is a very strong trans, from what I am told, it is basically a TH400 with a 4th gear that is electronically controlled, so it will need a computer module to run in a truck without an ECM, which runs about $600 -750.

Now the only thing I didn't mention is what else is needed to make the change, like driveshafts, shaft yokes, U-joints and so on. When you start changing rears and front axles with different trannys, you may find that there isn't a direct bolt-on conversion from one unit to the other.

With any of these trannys, a good cooler in addition to the in-radiator cooler should be always considered, standard if planning on any type of towing.

As for the 14-bolt rears, most of those were either 4:10 or 4:56 ratios, I'm sure there are more with lower ratios but you would need a RPO guide to determine what ration any rear has if coming from a boneyard. Either that, or you have to crack the diff and check the numbers on the ring gear.

Good Luck!

 

[GunnyM1009]

I appreciate all the info everyone. I must apologize to the op though I didn't intend to hijack your post. Atleast this is still all relevant to you original question and all good need to know information.

 

[rhinob]

I appreciate all the info everyone. I must apologize to the op though I didn't intend to hijack your post. Atleast this is still all relevant to you original question and all good need to know information.

Hahaha, no worries! Hijack appreciated! This is a great discussion that I was hoping to spur. Lot's to consider...

 

[GunnyM1009]

Well it has helped me out. I believe after all this I may just order a good b&m or red alto rebuild kit for my th400 and add an external trans cooler.

 

[patracy]

Oooh, missed the trailer. 28ft trailer for a blazer is a bit much IMHO. Granted, I've pulled stuff with my M1008 that is questionable. But there's no way I'd want to routinely do it.

 

[GunnyM1009]

Well that gives me good food for thought. That 28ft belongs to my father in law. I just didn't want to have to buy one if i could borrow one a couple times a year. Even if I bought one it would have to be atleast a 20ft and I just dont know if 8ft is going to make enough difference.

 

[Bob H]

Well that gives me good food for thought. That 28ft belongs to my father in law. I just didn't want to have to buy one if i could borrow one a couple times a year. Even if I bought one it would have to be at least a 20ft and I just dont know if 8ft is going to make enough difference.

Borrow his truck when you borrow the camper

 

[Ilikemtb999]

Whenever the th400 goes in mine I'd probably end up going nv4500 if I can swing it. I guess if I was staying auto I'd much rather go 4l80.

 

[rustystud]

Whenever the th400 goes in mine I'd probably end up going nv4500 if I can swing it. I guess if I was staying auto I'd much rather go 4l80.

The problem is the cost ! The control module is over $600.00 just by itself ! Then you need to shorten the rear driveline and lengthen the front. Then there's the connecting to the transfer-case issues ! Just much easier to rebuild the TH400.

 

[rustystud]

I was just going through my manuals today and found my TH4L80-E service manual. I totally forgot how much it really costs to rebuild one of these units. The last one I priced out was over $3000.00 just in parts ! Then there is the whole "upgrade" thing. For a "little" extra you can make it a 4L85-E or just a "little" more money you can make it an 4L90-E ! Where does it stop !?!?!? Knowing myself I would upgrade until I had every optional piece of equipment in this thing ! Red Alto clutches, Koleen Steels, Kevlar Bands, Heavy duty roller one-way clutches, all Torrington Bearing thrust-washers, "300 M" shafts, I can't help myself !

 

[richingalveston]

with the HP of a cucv, the stock built 4l80e should be all you need. I had mine rebuilt twice and each time it was less than $800. The first re-build got overpresured by a TCI controller. The second time I had no problems because I threw the TCI away and bought a US shift1 controller.

The US shift one controller works great. with wiring harness it is approx. $600. If I did not make the mistake of buying TCI the first time my 4l80e would have cost me about $1600 and I bought the extra parts to convert a 2wd 4l80e to 4wd.

I did the labor myself(except for rebuild). If you have to pay someone to remove rebuild replace and reconfigure cross member and shift linkage you will spend at least another $1000 or more on labor
TCI controller was $850 with wiring harness and it toasted a brand new rebuild that cost me $600 to have done.

Just get a standard rebuild and the US shift controller and you should be in it for less than $2k

 

[Ilikemtb999]

The problem is the cost ! The control module is over $600.00 just by itself ! Then you need to shorten the rear driveline and lengthen the front. Then there's the connecting to the transfer-case issues ! Just much easier to rebuild the TH400.

All things that really aren't that much work. I have custom driveshafts already and a great driveshaft shop that doesn't charge much. The controller is really the only big expense other than the trans. Like it was stated I think under $2k is very doable.

Or spend that on an nv4500, or go dirt cheap and get an sm465.

 

[rustystud]

All things that really aren't that much work. I have custom driveshafts already and a great driveshaft shop that doesn't charge much. The controller is really the only big expense other than the trans. Like it was stated I think under $2k is very doable.

Or spend that on an nv4500, or go dirt cheap and get an sm465.

The SM465 is not an overdrive so nothing gained over the stock TH400. As far as the rebuild cost, if they just "freshen up" the transmission then yes it will only cost between $600.00 to $800.00 . If it's a true rebuild then your looking at a minimum of $1000.00 to $1500.00 . Then if you go with the expensive performance parts it really gets scary ! Having worked at transmission shops in the past I'm very aware of all the little tricks to keep the cost down for the shop, yet still bill the owner for a rebuild. When your rebuilding for a "transmission repair only shop" your expected to rebuild 6 to 8 units a day ! There is no way you can do a total rebuild in that amount of time, yet alone a quality rebuild.