Kinda got carried away..... M1028 rebuild

[86m1028]

Yeah Recovery, I'm thinking 700R4 might have to be next. I already have a factory tv bracket and OEM tv cable, as well as the correct taller case adapter. And I know where I will buy the rebuilt tranny. However I am still struggling with what to do about the transfer case. The 700R4 output shaft will not mate with the NP208 due to spline count, so the only way to make the two work together is to purchase a special output shaft from Advance Adapters to the tune of $500 bucks or tear into the 208 and change the female input. And my thinking is, instead of tearing into the 208 I may as well go ahead and install a bullet-proof NP205. Your thoughts? I'm spending my daughter's inheritance so I don't care what it costs. Decisions, decisions.

Hey Sharecropper
Glad your happy with the 60 spring plates.
Did you move your axle back ?
Please reconsider putting a 700r4 in that great truck !!!
Those are rated 1/2 ton for a reason.
Hope you have some speedy recoveries.
Keep us posted on your progress.

 

[CUCVLOVER]

Have you thought about any of the gear vendor units?
They have a transfer case unit https://www.gearvendors.com/4x4.html

 

[CUCVLOVER]

Have you thought about any of the gear vendor units?
They have a transfer case unit https://www.gearvendors.com/4x4.html
Then the usual stuff. https://www.gearvendors.com/4x4gm3s.html

 

[Chaski]

The 700R4 is a glorious upgrade (as long as it is built correctly). I love mine behind a stock 6.5.

It really helps out with crawl ratio.

For example, take a pickup with a TH400 or a 4L80E and a NP205. Tough as nails, but a horrible crawl ratio. The 4L80E and TH400 both have a 2.48:1 first gear, the NP205 has a 1.96:1 low ratio, and you have 4.56:1 axles. Crawl ratio is 22.16:1

Next... Stock M1008.. TH400, NP208 and 4.56 axles. 2.48(TH400) x 2.61(NP20 x 4.56 = 29.5:1 crawl ratio.

Even better... 1008 with a 700r4. 3.06(700r4) x 2.61 (np20 x 4.56 = 36.4:1 crawl ratio.

Personally I have a 39:1 crawl ratio with 37" tires. Compared to my buddies stock drive train m1008 (29.5:1 ratio) on 37" tires there is a pretty big difference on steep climbs and navigating obstacles deliberately.

I know everyone lives in different geographic areas, but be mindful that a gear vendors or a 4L80e will not help out your crawl ratio.
Only a 700r4 will.

 

[Sharecropper]

Hey Sharecropper
Glad your happy with the 60 spring plates.
Did you move your axle back ?
Please reconsider putting a 700r4 in that great truck !!!
Those are rated 1/2 ton for a reason.
Hope you have some speedy recoveries.
Keep us posted on your progress.

Reply to 86m1028 - I haven't moved the front axle back to stock location yet because my back hasn't stopped hurting. This is on the list to be done but will probably be grouped with the transmission work. Thanks for asking.

 

[Recovry4x4]

The 700R4 was in 3/4 ton trucks as well. The early bugs have been worked out and a decent rebuild can handle 3 times the output of a 6.2. Before you consider not using the 700R4, ask the many many members that have done the swap what their opinion is. You will not find a single disappointed person in the house.

 

[Sharecropper]

The 700R4 was in 3/4 ton trucks as well. The early bugs have been worked out and a decent rebuild can handle 3 times the output of a 6.2. Before you consider not using the 700R4, ask the many many members that have done the swap what their opinion is. You will not find a single disappointed person in the house.

I am indeed going with a built-up 700R4 from Mad Dog Transmissions in Cummings, Georgia - http://maddogtransmissionexperts.com/home/2665592 I have also decided to simply go into my NP208 and change the female imput to 27 spline to match the output shaft of the 700R4. Because my truck has only 13,400 original miles and most of those were accumulated over a 25-year time period driving around a National Guard base in Arizona, I see no need for going any further with a mild rebuild of the case. Now my decision is whether to buy a used 27 spline input on Flea Bay or order a new part from GM. And I need to find the section in the TM for tearing down / rebuilding the 208.

 

[Sharecropper]

Well while I am accumulating the cash for my 700r4 swap, I decided to proceed with installing new HMMWV high-back seats. The first step in this process was to, ahem, remove the darn factory bench. I got this out easy enough, then I established a centerline mark on the cab bottom to align with the centerline of the steering wheel. I accomplished this with a level, straight edge square, a chalk line, tape, and magic marker. Here are some photos of the process along with the seats I plan to install -

 

[Sharecropper]

Next I sat the HMMWV seat in the truck and spaced it up with blocks of wood to get it to the height it needed to be. This was determined to be around 2 inches above the cab bottom, so I fabricated a wooden frame from 1" x 1-1/2" stock and determined how the tabs had to be added to align with the factory bench seat holes. I quickly determined that I would need to add a support leg on the side closest to the truck centerline. Here's a few photos of the wood model -

 

[Sharecropper]

The wood model fit perfectly, so the next step was to duplicate the design in steel, 1 for the drivers seat and another with the tabs on the opposite sides for the passenger seat -

 

[Sharecropper]

I then media blasted and primed both seat frames and fit the new HMMWV seat adjusters onto them with self-threading bolts -

 

[Sharecropper]

After I got the HMMWV seat adjusters properly fastened onto the steel seat frames, I took them back off and painted the frames with 383 CARC Substitute -

 

[Sharecropper]

Here are the new seat frames and HMMWV seat adjusters bolted in the truck. I will post more photos tomorrow after i get the seats installed. Note the new HMMWV seat belts!

 

[richingalveston]

awesome work, I like the Hummer seat adjusters. The adjusters in the 1009 are very sloppy and seam to be a lot taller. I have suburban seats on the 1009 bases and would like to replace the slides.

I like those slides, do you have to buy the seat to get them. I don't like the hummer seats for an 09, back is to low.
curious if the seat adjusters were sold separately.

truck looks great
Rich

 

[unaffiliated]

I like the seat mounts you made. The build quality is superb just like everything else on this truck. Just curious, what are you going to do with the factory bench seat? If I remember correctly, it is like brand new. I am interested if you think you might want to sell it. Thanks.

 

[Sharecropper]

awesome work, I like the Hummer seat adjusters. The adjusters in the 1009 are very sloppy and seam to be a lot taller. I have suburban seats on the 1009 bases and would like to replace the slides.

I like those slides, do you have to buy the seat to get them. I don't like the hummer seats for an 09, back is to low.
curious if the seat adjusters were sold separately.

truck looks great
Rich

Hi Rich;

The slides come with the HMMWV seats, so if you wanted to try to use them under your suburban seats you would need to find a source for just the slides. You would also need to fabricate custom frames like I did. I am confident the M1009 frames would need to be different than the truck frames. If you were to fabricate custom frames you could solve the issue of the low back. If you were closer I would try to help.

Thanks for the compliments. Been a six-year labor of love. Still a lot to do.

 

[Sharecropper]

I like the seat mounts you made. The build quality is superb just like everything else on this truck. Just curious, what are you going to do with the factory bench seat? If I remember correctly, it is like brand new. I am interested if you think you might want to sell it. Thanks.

PM sent.

 

[Sharecropper]

OK here is the finished product with the new HMMWV seats installed onto the custom seat frames. Sooooo much more comfortable than the factory bench. By the way the discoloration on the seat is pure sweat. Now I plan to design and build a custom console and will post additional photos as the project progresses. Thanks for looking.

 

[bikeman]

I debated doing this with my M880 and some HEMMT seats I picked up... now this is going to make me think even harder!

 

[Jozseph]

OK here is the finished product with the new HMMWV seats installed onto the custom seat frames. Sooooo much more comfortable than the factory bench. By the way the discoloration on the seat is pure sweat. Now I plan to design and build a custom console and will post additional photos as the project progresses. Thanks for looking.

Sharecropper, "Outstanding" design and fabrication work!

You should consider manufacturing and selling these seat frames