How common is this?

[holyford86]

Just recently, on a road trip to an offroad park my transfercase decided I was going too fast and went out, leaving me with low range only... I changed the case on the side of the road and went home (thank god for good friends).
I tore the case (1354M) down when I got home and discovered that the oil pickup tube had torn right at the oil pump. Further dissection showed me the reason for my loss of forward motion was a burned out range selection shift fork (the one closest to the planetary gearset). I'm assuming that the loss of lube to the front of the case is what caused this failure. I got ahold of a 1354E and swapped out the range selection collar, fork, oil pump, mainshaft (showed signs of less wear than the one I pulled out which was otherwise fine), and oil pickup, (all the bearings, gears, chain, lockup fork, case parts showed no signs of abnormal wear), reassembled and reinstalled the case (1354M cases are hard to come by around here).

How common is this type of failure?

 

[Snoranger]

The oil pump failure is one of the biggest issues with these cases. The tab on the pump usually bends, breaks, etc and allows the pump to spin. If the pump spins, the pickup breaks.... No more lube!

Its also common on the 13-56 (the 13-54s fullsize brother).

 

[holyford86]

The tab on the pump was fully intact (first thing I thought of) there was a groove about 1/32 worn into the case though. I verified that the tube had enough slack when I installed the new (to me) pump in the case and it seemed fine (slight slop in it but not enough to hit anything). Is there any way to help prevent this (revised pump case, etc)?

 

[F150hybred]

I had one go that way too. Exact same way. More common of a failure than not.

 

[racsan]

if that were to happen, would the truck still be driveable or would the transfer case eventually lock-up altogether? i could possibly live with the loss of 4wd (though i wouldnt like it) but id hate for the truck to be out of service completely.

 

[country0001]

Just recently, on a road trip to an offroad park my transfercase decided I was going too fast and went out, leaving me with low range only... I changed the case on the side of the road and went home (thank god for good friends).

Mine did this today while on a road trip to DFW. I lost 2 hi and 4 hi,but have 4 lo.

Thank God I am picking a tcase up tomorrow from a fellow TRSer.

Can't wait to tear mine down and find the problem

 

[holyford86]

Mine did this today while on a road trip to DFW. I lost 2 hi and 4 hi,but have 4 lo.

Thank God I am picking a tcase up tomorrow from a fellow TRSer.

Can't wait to tear mine down and find the problem

I'd dare to bet that it lost lube and ate the range fork, just like me.

 

[country0001]

The tranny fluid I drained out of it is a dark metallic gray and looks nothing like the Mercon I put in it.

I'll tear it down next week when I get back home and report back on it.