Xfer case issues

[arctictraveller]

I have a Borg Warner 1356 manual transfer case. Back in November, it was popping out of 4 low, so on the way to Baja I stopped in at Agile and had them remove the unit for me. I then tore it apart for inspection and found the "C" clip from the end of the shift shaft laying in the bottom by the drain plug. Close inspection of all the parts only showed slight wear on the shift hub which I replaced in an abundence of caution. All other parts seemed to be in excellent condition, so the clip was replaced and I put it all back together. After that, shifting was positive and crisp, it went into 4 low easily and it stayed there. Fast forward to last week, and suddenly it went back to it's old, bad habit of sloppy engagement and failure to stay in gear. As soon as the weather warms up a bit, I'll pull it out again, and I fully expect to find the clip missing again, but the problem is, I don't understand why it's coming off. I'll inspect the shift shaft C clip groove closely along with the clip, but they looked fine before. I suspect something is forcing the shaft to move outboard, placing a high sideways force on the clip, popping it out of the groove. Most likely I'll order another shaft and clip, but if anyone has any idea what might be going on, I'd love to hear it as I have enough projects already and don't want to pull the xfer case a third time................ Thanks.

[BMWBILO]

I had the same problem with my van that was converted by Advanced. Take off the shift boot, put it in 4 low and see how much clearance you have between the shift lever and the hole in the floor of the van. If the shift lever is almost touching the hole you may have to trim it some. The drivetrain has some movement when you let off the gas, if the lever is too close it may be hitting the hole and knocking it out of 4 low. I did what you did and took my transfer case out and had it looked at. My mechanic said it was fine. I finally searched the junk yards and wound up taking the shift lever pivot out of a Ford pickup and replacing the junk pivot that Advanced cobbled together. The Ford one was gated, you have to push the lever towards the seat and then back to put it in 4 low. I finally wound up having my transmission guy install the shorter 4x4 output shaft in my transmission and I installed an NV271 transfer case.

[arctictraveller]

Thanks for that. I did check the shifter clearance and actually added some with a BFH and now have plenty. When I took the transfer case apart, I found a "C" clip at the bottom of the case. It belonged on the end of the shift shaft and I suspect it's come off again. The question is why? I'll have it out soon and hope to find something concrete. Thanks again.

[arctictraveller]

Update, I pulled the transfer case and opened it up to find everything in place. The C clip was on the shift shaft just like it belonged. I tore the case down completely, cleaned everything up and inspected all the parts closely. I also measured the end play of the planitary gear set which has an allowable slop of .060, and found only .040 play. The shift shaft was tight in the bore, with only .004 clearance. All parts looked great visually, so my next step was to take it to a local transmission shop that claims to have rebuilt dozens of these. He immediately spotted the center bushing in the planitary half way out of it's bore, and thought it may have been caused by worn gears. After looking at all the parts, he recomended replacement of the planitary gear set and the slider gear that engauges with it. He couldn't positively point to a problem with it, but his experience said to replace it. My experience says I should be able to measure the wear in the parts to diagnose, but after extensive searching I've been unable to find the specifications, nor did the rebuilder have them, so it's a guess not a scientific diagnosis. Not wanting to do this a third time, I asked if he would guarantee the new gear set would fix the problem and he said yes if he re-assembled it. So, I left it with him. It looks like the first $500 I put into it in November was a waste, but wanting to move on from this problem for once and all, I decided to take a chance and dump another $500 or so into it, at least if it doesn't work this time, I can take it back.

[TomsBeast]

I'm with you, I'd want to figure out why the thing failed, address that, then replace the abused parts that wore or failed as a result of the root cause. Most shops open 'er up, look for damage, replace the obvious wore out stuff, give the van (and the customer) a pat on the ass and send them on their way.

With the planetary bushing coming out of it's bore, it sounds to me as though you found another symptom, but perhaps not the cause.

Back to the circlip coming off: that says to me the shaft is being pulled out of the case (not normal), or the internal gate plate is being twisted. I'd look in two areas.

1) the internal gate plate has a heavy duty mouse trap spring for the detent, that loads the gate plate and in turn, the shift shaft. Not all of that load is orthogonal (sorry, 90deg) to the shaft. I'd look at that. I'd look at the internal gate plate's splines, and the shaft splines. If loose, the plate could flex at an angle to the circlip, could push the circlip at an angle, much like getting a screwdriver under a circlip when you don't have snap ring pliers, and make it come out of it's groove and off the shaft, then the shift forks out of their fixed locations. (I think you replaced or are replacing those).

2) I'd look outside the t-case, at the outer linkage to see if something is tugging on the shaft. Static, it might not be obvious, but under 4x4 low heavy load, my engine torques over a fair amount. A lot more than 2wd high. I'd look at the linkage bar, that connects the shifter to the t-case shift shaft, for rub marks. Looking to see if the linkage is binding under heavy 4x4 load (I know you USE your 4x4). Mine linkage uses the Ford urethane bushings, same as a Bronco, and would just 'pop off' if tugged on, side loaded, too hard.

If the t-case shifter itself were hitting the body though hole, it might side load the shift linkage, but it's hard to imagine that load transferring to the t-case shift shaft, since the shifter, the T-case, and transmission are all bolted together as one (at least on my 1356 and E4OD it is). I would suspect that, but wouldn't totally rule it out, either. I can tell you that UJOR uses hiem rod ends on his conversion shifters he sells, maybe to eliminate some side load problem he's seen? Who knows.

Don't underestimate engine, transmission, and t-case 'roll', as a result of being in 4x4 low. As an example, adding an aftermarket super lower gear to a Suzuki Samurai's t-case is know to break engine and t-case mounts, because of this effect.

I had a similar issue with an AWD GMC Safari van. My local transmission shop tracked it down to worn engine mounts. Under torque, like leaving a stop light while in a hurry, the engine would torque to one side and make the exhaust (I think it was) rub on something, made it sound like the transmission was not long for this world, on my 130k mile van. We replaced the engine mount, and the problem went away.

I hope you get it sorted out, if you haven't already.

[arctictraveller]

Thanks for the thoughtfull reply. I've looked at most of the issues you have mentioned and not found any smoking guns. One thing I'm not aware of is how much a "new" engine mount moves. I've used a pry bar to move the engine around while watching the linkage and didn't see anything excessive, but engine torque is a lot stronger than I am. So, I took the thing to a well known transmission shop that claims lots of experience with the BW1356. He condemed the planitary gear set and said he would rebuild it for under $500. Wanting to end this project I left it, but a couple days later he called back to tell me that my particular version has a PTO option and a new (updated) planatary for my version was North of $700 plus labor and other parts. Well, plenty of places sell rebuilt units for less than that, so I took it back and reconsidered my options. Meanwhile, I had placed a "wanted" ad on my local 4wd "buy, sell, swap" Facebook page and got a quick reply from a guy who has one for $100. It was from an F150 he parted out with an estimated 170K miles. That's a lot, but plenty of pickups almost never used 4wd and even less often used 4wd low. So, tomorrow I'm meeting him and will tear it down prior to purchace. If it all looks good, I'm willing to take a chance and put it in to try it out. For only $100, it's not a big risk, and seven times less expensive than just a new improved planatary. Or, I might just use the planatary if it turns out to be better than mine. Fortunately, I'm not in a huge hurry since my next currently scheduled trip isn't until June. Thanks for the advice, I'll let you know.

[TomsBeast]

Originally Posted by arctictraveller

Thanks for the thoughtfull reply

my pleasure

I feel like I know a lot about the BW1356

I wish you lived closer, I'd offer a second pair of eyes on the internals.

I also have a spare planetary from my case with the hole in it.

I also have a second oil pump arm, that I modified to cure the dreaded 'grooved case' issue.

[sierraskier]

I have a '98 E350 with a BW 1756 that was also popping out of 4wd low. Before I started looking into this not sure I even knew what a transfer case was, so certainly do not have the resources/knowledge to pull it or tear it apart [emoji4]

Took it to the shop who is telling me transfer case has "failed". Through talking to them and one other local resource I trust, it looks like a rebuild is the best route because as I understand it:

1) a new BW1756 are hard if not impossible to find
2) some of the connections/shaft into the transfer case would need to be customized

I'm being told a rebuild kit, rebuild and replacement would be in the ~$2500 range. I'm just looking for some validation on this and any other thoughts/ideas

I should mention I very rarely use 4 low as I don't off-road the van a lot, 98% of the time it's in 2wd, 4wd high on fire-roads or in snow, very rarely (once or twice a year maybe) 4wd low on steeper/chunkier grades for very short stints or to get moving in deep snow.

Thanks!

Edit: SMB build sheet

[arctictraveller]

Did you mean you have a 1356? Perhaps a 1756 is more expensive, but without knowing exactly what "failed" it's hard to determine the cost to rebuild. A general rebuild kit with bearings, seals, gaskets and a chain is pretty inexpensive ($200?) but if your planatary gear set is shot, depending on if you have a PTO option, it will be more. I think most shops simply take a quick look and then say a rebuild is needed, without really determining what the problem is, since it's easier to simply throw new parts at it. You can buy an off the shelf rebuilt unit from several sources, often times for less than the cost of a rebuild at a local shop. $2500 seems a bit high unless you have case damage or need new gears. Once taken apart and cleaned up, reassembly only takes a few minutes. I also wonder why you would need new linkage unless yours is shot. If so, that could be the reason it comes out of gear. These places offer off the shelf rebuilt units and there are others, try Google. Shipping does add to the cost though. Keep us informed...................

Transfer Case Express, Inc. · transfercase makes & models for transmission shops & car repair services


https://www.midwesttrans.com/1356.html

Transfer Cases - Rockland Standard Gear, Inc.

[TomsBeast]

I'm with Arctictraveler, someone must have written down the numbers wrong, in researching parts and repairs for mine, I never heard of that gearcase. You likely have a 1356.

In either case, ahem, here's a handy article on identifying 4wd gear cases

Transfer Case Spotter’s Guide

They show a 1356F which is the electrically shifter one (junk, as the solenoids often go bad after as little as 5-6 years of wet use). But if yours is a manual 1356, just ignore the motor and wires in that picture, everything else will be the same. There are also markings on the outside of the t-case that give away it's number. That picture is oriented such that 12 o'clock is toward front of the van, 6 o'clock toward the rear. The cast-in 'spokes of a wheel' shown at 8 o'clock, and the 'grate pattern' shown at 6 o'clock, are indicative of the 1356.

If yours is truly bad (it's not just a linkage issue) and your local shop can't handle repairing it, then yeah, a remanufactured unit is the way to go (you don't need a 'new' one).

If you want to see the rebuild process w/good pics, even if you aren't going to get your hands dirty on this deal, there's a writeup article on a Ford Bronco forum. It will make you a better informed customer when shopping for a shop.

Rebuild your own transfer case. BW1356 - Ford Bronco Forum