Sprinter 4WD Conversion Idea, GMT-800 IFS.

[luthj]

Just bought a used planetary out of a 246 Tcase. It should have the same 16mm input bearing, and thus fit the 242D. The overhaul kit will arrive this week, so I will get it buttoned up over the weekend. Hopefully I can also finalized the UCA choice. At which point its just drudge work until I order some steel.

 

[luthj]

Ding Ding Ding, we have a winner. 97-04 F150 2WD UCAs. Same BJ taper and size (might need a slight ream to adjust depth), and the offset clears the coil spring. I got one on order, and should be cooking by the weekend.

 

[b dkw1]

If you can find a used set of these https://www.ebay.com/itm/For-Ford-F...618456?hash=item364e672c98:g:~MUAAOSwLBlc8VWO
(early f250/f350s had them) they would be a great look and fit for you. They are 16x7 with 4.3" BS....they are pretty desirable for the old ford truck gang so not as easy to find as they used to be..

Those also came on E250's and 350's. Also excellent wheels. The Cheby wheels are also made by Alcoa. You can't go wrong with any forged Alcoa wheel for strength.

 

[b dkw1]

Using the F150 upper arm also opens up a lot of aftermarket options if you want to go that way in the future.

 

[Stingy49]

Exciting to see the tone ring adapter working well! Glad to see progress is still being made.

 

[luthj]

Exciting to see the tone ring adapter working well! Glad to see progress is still being made.

Your going to see a lot of obvious progress soon. ?

 

[luthj]

Okay, got off work early, and I am cracking away.

First off got the ford UCAs. They are looking good. Model shows good clearance.




IMG_20190621_143926817 by J Luth, on Flickr

IMG_20190621_152158744 by J Luth, on Flickr

They fit the GM knuckles. However I need to open the hole up a little, as they don't go deep enough to pin the nut.

IMG_20190621_152207535 by J Luth, on Flickr


I am also baking my Tcase halves. I have the last pieces in the oven to swap the bearings. Heat the cases up to 325-350F, and the bearings drop right out. Though the blind caged needle bearing is the final test. The kit I bought is short one output bearing. Not a big deal, as mine are in good shape.

IMG_20190621_150219850 by J Luth, on Flickr

I swapped the input shaft over to the new planetary. I may need to change that to the new inverted style depending on which intermediate shaft I end up with. So will hold off on final assembly until I have those parts.

IMG_20190621_142813562 by J Luth, on Flickr

IMG_20190621_150525277 by J Luth, on Flickr


IMG_20190621_150737034 by J Luth, on Flickr

 

[luthj]

Here is the input shaft used on the Jeep NAG1 241. Its 26 external splines. It looks like it accepts the 16mm wide input bearing. I just need to track one down, and the matching adapter case.

 

[luthj]

Another milestone, I connected the output of the FWB converter circuit to the ESP module Using a 980hz source signal, the ESP module reports 96mph. My math says it should be 91mph. However I don't know what exact tire diameter the module is programmed with. So a 5% deviation is likely just error on my part.

The ESP module is duty cycle agnostic, so it just counts pulses. It doesn't need an AC signal, a basic 0-5v square wave works just fine! Which simplifies the FWB output design substantially. I think i am ready to order a project box, and prototype shield for the UNO, and make a full-on prototype.

IMG_20190622_100050170 by J Luth, on Flickr

 

[luthj]

Finished updating the model for the Ford UCA. Bumpsteer, camber gain, and caster gain are all looking good. It doesn't look like I will need clearance cuts for the UCA bushings either. Engine mount towers are in their final position. I am almost ready to order shocks, springs, and lower spring collars.



The only minor issue is the front bushing plate interferes with a mounting bolt. So I need to notch or move it a bit.

 

[luthj]

For some reason, fox refuses to publish detailed technical data for the individual. You almost have to sign a dealer agreement to get it! I am managing though.

Attached is a PDF with the common fox eyelet offerings.

Here is the 2.5 relevant list. Note that the 2.0 shock with 7.8 shaft uses a shallow thread, and is not compatible with the 2.5/3.0 deeper thread and vice versa.

 

[luthj]

I got some more info on shocks. The fox performance series 2.5s will not accept the offset spring perches used on the race series. Grrrr. The lead time for custom factory series starts at 8 weeks... Not going to work for my schedule.

I was looking through the fox Truck application guide. Its pretty sparse on details, but it does list overall length for a couple of truck applications. Including Tundra and GM 1500 series.

The 07-18 1500 coilover (fox 880-06-525) looks like it might work with some modifications. I would swap the lower eyelet for a shorter one (about 40$). I don't really know what springs it comes with, so thats another 120$ per spring.
Specs are 20.34 ext, 14.98 comp, travel is 5.36". I need 5" total travel, so that's just barely enough. The big advantage is they are in stock all over. Second, I can swap eyelets and spring perches around for reasonable money. The disadvantage is that I will be buying a spring which is unknown rate. The second disadvantage is they are like 800$ each! These had better be the last shocks I ever buy for this rig... There are IFP versions of this shock that are much cheaper. They would likely need tuned manually to get right for the van though. Hmmmm.

 

[Len.Barron]

The second disadvantage is they are like 800$ each! These had better be the last shocks I ever buy for this rig...

That's always been the hit on coilovers...they are fantastic...but ...you pay for every bit of it. One of those things you just have to grit your teeth and press "pay"

 

[luthj]

I got some info on the fox GM 1500 units. They are using a 3x14.2x700lb spring. Which works for a lighter van (3200-3600lb front), which I am putting a kit together for. I think my van would benefit from a 750 or 800lb spring. I am leaning towards one of these off-the-shelf units, but I need to take a look at King and other brands to see if they carry a GM 1500 version which would likely also fit.

 

[luthj]

I think I have convinced myself to just deal with the cost. King isn't much cheaper, and I don't want to deal with a blown 1.X" shock in the middle of nowhere.

These shocks will all fit.

PART NUMBER     EXT. LENGTH     COL. LENGTH     TRAVEL         TOP MOUNT     BOTTOM MOUNT     RESERVOIR    Price
880-06-525     20.34         14.98         5.36"         TM         Eyelet         Remote (ADJ)    2,049
880-02-525     20.34         14.98         5.36"         TM         Eyelet         Remote        1,699
883-02-028     20.37         15.02         5.35"         TM         Eyelet         2.5 (IFP)    1,399

I needed to raise the tower another inch. That's basically all the room there is. And no, I don't want more lift! Basically all of the strut gusset needs to come out. About 10 spot welds and some grinding will do it. I can tie to the floor (its about 12 gauge thick). The good news is I don't need to swap the fox eyelet, which gives me more room to work with the factory bumpstop.