Sprinter 4WD Conversion Idea, GMT-800 IFS.

[Mwilliamshs]

Driveshaft length plays a large role in angularity.

 

[b dkw1]

I wouldn't sweat a couple degrees on the pinion Joint. It will be enough to move the rollers around and keep them lubed. It will also help prevent brinelling.

 

[luthj]

Yeah, with the front axle disconnect, I won't have any shaft vibrations cruising in 2WD, so thats less of a concern. I just don't want annoying NVH stuff in 4hi.

 

[Len.Barron]

Yeah, with the front axle disconnect, I won't have any shaft vibrations cruising in 2WD, so thats less of a concern. I just don't want annoying NVH stuff in 4hi.

that was one of my greatest concerns on my build, with the solid aam9.25 up front and no disconnect/lockouts I knew my shaft would be spinning all the time and unloaded so if there was anything it didn't like about the angles it would hum...thankfully I haven't had any of that, even at 80+ on the hwy (which I rarely do).

 

[luthj]

So, I have an unanticipated design issue. Basically the 241 case has an offset front flange. GAH! The flange is about .57" taller than the 242. Which creates a bit of a problem.



IMG_20190717_164550979




This is all the farther they will go. Its about 1.2" or so. There are two interferences. First the input shaft is too long. I can probably source a shorter one, or switch to the wrangler style in the first photo. But that won't solve the seal plate from interfering with the intermediate shaft/collar. There is enough material there I can cut one or the other down I guess... My only other option is to make a 1.3" tall spacer and use longer studs.

The only other thing I can think of is I could try cutting the intermediate shaft down 1/2", and then using the short input shaft. That might get me enough clearance. The splines in the intermediate shaft would be pretty short, 1/2" or so.

IMG_20190717_173134560

 

[shade]

Will a spacer screw up the design of your custom sub-frame? If not, I'd go that route. It would be easier to add that spacer to a replacement case while in Mongolia than cutting down shafts, and the longer shaft connection will be stronger. 1/2" isn't much meat.

 

[luthj]

I see some NP205 spacers for reasonable money. Anybody know if the 205 uses the same 6 bolt pattern?



I also see this 3/4" atlas adapter, AS-8603. It sounds like its the right pattern, but I need to contact them. Combined with the shortest input gear NV/NP made, it may all fit together.

 

[luthj]

https://www.advanceadapters.com/tech-vault/1-gm-new-process-205/

Okay late 205 is the same bolt pattern as the NP241.

This circular bolt pattern is identical to that of the NP208/241

 

[luthj]

I believe this adapter will work. Its 1" long, So I will need to grind 0.165" off the stub adapter shaft. Should be pretty easy I think, and if needed I can adjust the Tcase clock as well. I will email and ask about fitment.

AS-0404 : 1" Spacer For Atlas Transfer Cases | Advance Adapters

The spacer adapter #AS-0404 is commonly used on Atlas conversions to alleviate fitment issues caused by variations in transmission output shaft lengths. Many transmissions have positive “stick outs” on their output shafts in relation to the ed...

www.advanceadapters.com

 

[luthj]

Moving on to more mundane things. The sprinter uses 3/16 bubble flare. There is a union right at the subframe, so thats an easy place to connect up. It uses M10x1 nuts, which will sometimes thread into the 3/8 fittings.



The brake lines I have use 1/4" tube, with that appears to be 7/16x24 nuts. The flare is SAE double style.

Originally I was going to make a new hard line from the union to the flex line. But with them being two different sizes, I need to find a reducing union. Its turning out to be a challenge, as female-female reducing unions don't show up with a google search. I really don't want to cobble together several fittings either...


It looks like I can use dorman 785-432. It shows 7/16-24 male, which fits the GM brake line. The female side is 3/8-24. I will need to buy some 3/8-24 nuts, and 3/16 brake line. One end will be 3/8-24 SAE double flare, the other will be M10x1 DIN/Bubble/ISO flare.

Dorman Products - Aftermarket Auto Parts & OE Solutions - 785-432

Brake Line Adapter-Tube-3/16 In. x 1/4 In.

www.dormanproducts.com

Looking even deeper, it looks like there are 7/16-24 nuts for 3/16" Tubing. So I think I can avoid the adapter all together.

 

[luthj]

Finished cataloging the donor transmission. Here is the highlights

All recent upgrades, including K2 drum and rear sun bearings. F2 sprag is the newer design as well.

All clutches show very minimal wear (less than 0.01mm) Many still had factory part numbers visible.

Only the K2 clutch showed some wear, with 0.02mm per friction.

The B1 drum showed some wear on the outer engagement splines with the disk.

All bearings in good shape.

K1: single sided frictions, 10 total, 2.07mm each
K2: Inner double frictions, outer steels. 10 total. 2.12 and 2.8mm respectively
K3 Single sided frictions, 8 total, 2.13mm each.
B1: Single sided frictions, 6 total. 2.07mm
B2: Steel outers, double friction inners. 10 total
B3 Steel inner (4), double friction outer (5).

All snap rings and backing plates matched the ATSG tables. B3 doesn't match the table, with 1 additional friction. Several clutches were not maxed out per the table (sprinter may have even higher plate counts). So this trans, despite being a W5A580 is only medium duty.

I have attached an Excel sheet with the clutch buildup. You can ignore the clearance and drum total numbers, as those are random for now. When I got to build up the trans, it will allow me to check clearance before I build up the packs.

 

[Len.Barron]

Moving on to more mundane things. The sprinter uses 3/16 bubble flare. There is a union right at the subframe, so thats an easy place to connect up. It uses M10x1 nuts, which will sometimes thread into the 3/8 fittings.

View attachment 528244

The brake lines I have use 1/4" tube, with that appears to be 7/16x24 nuts. The flare is SAE double style.

Originally I was going to make a new hard line from the union to the flex line. But with them being two different sizes, I need to find a reducing union. Its turning out to be a challenge, as female-female reducing unions don't show up with a google search. I really don't want to cobble together several fittings either...


It looks like I can use dorman 785-432. It shows 7/16-24 male, which fits the GM brake line. The female side is 3/8-24. I will need to buy some 3/8-24 nuts, and 3/16 brake line. One end will be 3/8-24 SAE double flare, the other will be M10x1 DIN/Bubble/ISO flare.

Dorman Products - Aftermarket Auto Parts & OE Solutions - 785-432

Brake Line Adapter-Tube-3/16 In. x 1/4 In.

www.dormanproducts.com

Looking even deeper, it looks like there are 7/16-24 nuts for 3/16" Tubing. So I think I can avoid the adapter all together.

Summit Racing has about the best selection of brake fittings I've found. Be careful when ordering 7/16" brake fittings, there are a lot of 7/16-20 out there as well.

 

[luthj]

I got the front two VanCompass skid plate models into the assembly. They were designed for my 2" lift and factory subframe. At a minimum I need to redrill some holes, and get a 1.5" spacer for the front attachment. Overall they aren't an great fit, with the new subframe, which is to be expected. All three plates are 1/4" AL and steel for the front. They are strong enough to jack from.

I also need to work around the diff mounts bulge (drivers side back). Either drop the skidplate another half inch, or cut out some clearance. Neither is desirable though.

 

[draaronr]

how are you cracking the transmission computer? for low gear, and abs etc?

 

[luthj]

I have a custom circuit that fixes the front speed sensor signals by adjusting frequency. The low range is handled by a canbus bridge that changes all four wheels speed values.