Transfer case BW1356 failure

[JackTuppVan]

"for what it's worth"
The Range Slider may not be as damaged as it looks.
The OEM Ford / Borg Warner slider teeth have a beveled leading edge,
the after market sliders I have seen are straight cut.

[TomsBeast]

As I mentioned, I decided to look around for a used t-case, rather than fix this one up. I'm with Arctictraveler, I want to know what's inside, particularly since pulling one of these things apart isn't rocket surgery, eh, brain science... uh, you get what I'm saying.

Disclaimer: I've been junkyard and swapmeet scrounging for 40yrs. I hate, I mean HATE crawling under junkyard carcasses rolling in the oily dirt or this time of year, often mud. Topside parts, no problem. Trim, seats, but geasey transmissions that might actually work, not my thing. I've done more than my fair share of it over the years, and have grown to dislike it. But I'm trying to recover from this deal inexpensively... hahahaha, Sportsmobile and inexpensive Now there's two words that look conspicuously out of place in the same sentence!

I figure out what vehicles the BW1356 came in, know they came with in manual and electric (don't want that) then flanged and splined outputs (not splined either) 4 possible combinations and I need 1 specific. I do a little pick-n-pull searching, gather my tools, two changes of clothes and shoes, and head out. Not very optimistic, this could be a total bust ending in frustration.

I had better pick up a lottery ticket because the first Bronco, at the closest yard to home, not only had the t-case I was looking for (manual shift, flanged output shaft), but someone had already removed it from the truck, taking the transmission for themselves, but leaving the t-case on a piece of clean dry carpet, completely in tact w/linkage. The only thing missing was to find it resting on a silver platter!

All I did was a quick function check, drain a little fluid and smell it, pink and new smelling, all good. I loaded it onto one of their makeshift wheel barrels and headed for the gate. I hardly got dirty, outta there in 20minutes.

Every wrecking yard trip should be so successful!

But wait, there's more, it get's better: I get it on the bench, pull it apart, and this thing is nice inside! It's got the updated planetary w/bronze thrust washer, the later updated model 4wd fork, good plastic inserts on the range fork that look new. The leading edge of the teeth on the range engagement sleeve look a little suspect... but Jack's pics and note on the non-symetrical angle grind that the factory teeth have was perfect. I took out my eye loupe and that's exactly what I've got. In fact, the entire thing looks like a reman unit with good parts, the bearings all spin very smooth. A $160 score!

I'll order a seal kit, and put it back together, hopefully next weekend

[86Scotty]

Nice all around!

[JackTuppVan]

I have heard of "junkyard jewels" before but never thought of using a eye loupe to verify.

Great find.

[larrie]

Excellent find. You got the lottery ticket yet?

[TomsBeast]

I came up with a fix for the oil pump arm trying to beat a groove into the case.

I added a 1-1/2" long piece of 1/2" diameter steel tubing onto the end of the arm, where it was hammering a groove into the case. Funny that this is a common failure on these t-cases, but Borg Warner nor anyone else for that matter, offers an updated arm.

I coped the end of the arm so the tube fit nicely, then broke out the oxy-acetelyne torch and brazed it with silicon-bronze rod.

pic #3 shows how the fix, the new end now spreads the load over a much bigger area.

[arctictraveller]

Great idea.

[TomsBeast]

I got it back together w/new seals, new oil pump, and back in the van 2 weeks ago. Tested all three positions on the jack stands, 2wd high, 4wd high, 4wd low, then road tested it. Everything worked bitchin' !

My GF surprised me with a week long resort trip to Cabo for my birthday. I was literally washing the grease off my hands and packing at the same time. I had an easier time relaxing knowing the van was back up and running, before leaving town.

Something I learned along the way:
Before deciding to look for a used case, I had ordered a new shift fork and high-low engagement sleeve, oil pump, and seals, parts to rebuild or have on hand during reassembly. At assembly I opted to use the fork from the pick-n-pull t-case, here's why;

The plastic inserts (earlier picture, in my oily hand) are two different densities. That is to say, the plastic fork inserts from the Pick-n-pull t-case are harder, more dense plastic. They look new, too. Slightly different, the new fork's plastic inserts, and the failed inserts I found at the bottom of my original t-case, are made from this this waxy, translucent polyethylene looking stuff. More flexible and pliable plastic. I sent the new aftermarket parts back.

I also inspected the failed t-case a little more closely on the bench. The corrosion around the shift shaft hole weakened the precision shaft bore, and caused the shaft to wobble. While playing with it, shifting it in and out of the various selections, I could imagine the shaft being cocked and bound up, such that the plastic inserts could melt and fall apart.

I'll bet that was the failure mode, chain of events so to speak. The salt (that I failed to wash off completely from my Bonneville trips, my bad) collected in this nook, reacted and corroded magnesium case, letting the shift shaft and fork, bind. The hole allowed oil to splash out (my hpop or turbo pedestal seals are leaking, so didn't notice more oil under there, also my bad) and run low. The additional friction from the shift fork binding, low oil, melted the plastic inserts. With the inserts laying in the bottom of the sump, the extra 1/8" clearance allowed the high-low engagement sleeve to drift, under deceleration, partially into low gear, grinding like a coffee grinder, rolling over the teeth.