Attention: TDR Forum Junkies 
Truck profile/history:
1998 12 valve, about 800hp/ 1600tq
with twins, 4wd, extended cab, long bed
DTT built automatic trans with billet input/output
Stock light duty transfer case, never been opened or serviced
Nearly 300k miles with 500+/- ¼ mile passes with high-boost launch in 4wd, lots of dyno events, too many burnouts/donuts to count.
Daily-driven all year, including towing and using 4wd all winter. I drive it hard.
Truck is on third motor (give or take) and I’ve broken transmission parts many times back when I drag raced (to be expected) including a billet input shaft (on the street). I haven’t done 4wd launches or burnoffs in at least a couple of years nor have I had the truck full throttle in that time because I DIDN’T WANT TO BREAK IT.
Truck has not been able to shift on the fly into 4wd for about 6 years, but I thought it was because of the front locker I had put in.
Transmission fluid change back in May, with just a couple thousand miles on it since.
Prelude incident happened a few weeks ago. I was out hotrodding across the desert, going fast. I took a left turn on a side street and accelerated pretty hard, but not breaking the tires loose. It slipped BADLY so I got off the throttle, then eased back in and it went fine. When I reached my destination I checked my fluid level, which was perfect and smelled good.
The actual catastrophe happened a couple weeks after that. I had been going fast again for a period of time then came to a stop sign and turned left, again accelerating but not super hard. I stayed in the throttle and eased into it even more and it started pulling pretty good when I heard a “pop” and the truck went limp.
Right away I pushed it into neutral and checked the motor by blipping the throttle. It sounded fine. All gauges normal; no trans heat. I tried Drive again but no luck so I got her off the road and called the tow truck.
At this point I assumed it was my billet input shaft which is bad juju. After my pity party I tore the truck down, removing transmission and transfer case. Input and output shafts looked perfect. I don’t know how to troubleshoot these things, and DTT is no longer an option, so I had nobody I trusted to check out the transmission. The fluid looked and smelled near-perfect, and when I pulled the pan and filter there were just a few tiny metal shards (very normal for my truck).
My buddy Mike said the transfer case did not sound normal when I spun it by hand, so I passed it off to Jason Burton of NWCustom in Spokane who agreed and had it rebuilt. It had a broken fork, stretched chain, and a gear that looked like a saw blade with sharp, ragged teeth. It seemed we had fixed the problem so I put it all back together and added fresh fluids.
I started it up and it never moved. If I put it all the way into 1 or Reverse it felt like it wanted to load, but ultimately did not. I may or may not have sat in the shop and cried.
So, out it came again much to my joy. Jason once again helped me out by referring me to a transmission man he said I could trust, and he tore it down while I watched. It didn’t take long to find the broken intermediate shaft. Again, shaft was stock. I went ahead and mailed the torque converter out to be opened and cleaned so I couldn’t regret NOT doing it. Everything else in the transmission looked EXCELLENT, clutches and all.
My theory is as follows: I believe that the transfer case was to blame, that it slipped (maybe because of the corner, maybe not) and when it fully re-engaged it shock loaded the intermediate shaft enough to snap it.
I wanted to share this to get any thoughts you folks might have, and also as a cautionary tale for anyone who’s having a mystery issue that could be transfer case-related.
1998 12 valve, about 800hp/ 1600tq
DTT built automatic trans with billet input/output
Stock light duty transfer case, never been opened or serviced
Nearly 300k miles with 500+/- ¼ mile passes with high-boost launch in 4wd, lots of dyno events, too many burnouts/donuts to count.
Daily-driven all year, including towing and using 4wd all winter. I drive it hard.
Truck is on third motor (give or take) and I’ve broken transmission parts many times back when I drag raced (to be expected) including a billet input shaft (on the street). I haven’t done 4wd launches or burnoffs in at least a couple of years nor have I had the truck full throttle in that time because I DIDN’T WANT TO BREAK IT.
Truck has not been able to shift on the fly into 4wd for about 6 years, but I thought it was because of the front locker I had put in.
Transmission fluid change back in May, with just a couple thousand miles on it since.
Prelude incident happened a few weeks ago. I was out hotrodding across the desert, going fast. I took a left turn on a side street and accelerated pretty hard, but not breaking the tires loose. It slipped BADLY so I got off the throttle, then eased back in and it went fine. When I reached my destination I checked my fluid level, which was perfect and smelled good.
The actual catastrophe happened a couple weeks after that. I had been going fast again for a period of time then came to a stop sign and turned left, again accelerating but not super hard. I stayed in the throttle and eased into it even more and it started pulling pretty good when I heard a “pop” and the truck went limp.
Right away I pushed it into neutral and checked the motor by blipping the throttle. It sounded fine. All gauges normal; no trans heat. I tried Drive again but no luck so I got her off the road and called the tow truck.
At this point I assumed it was my billet input shaft which is bad juju. After my pity party I tore the truck down, removing transmission and transfer case. Input and output shafts looked perfect. I don’t know how to troubleshoot these things, and DTT is no longer an option, so I had nobody I trusted to check out the transmission. The fluid looked and smelled near-perfect, and when I pulled the pan and filter there were just a few tiny metal shards (very normal for my truck).
My buddy Mike said the transfer case did not sound normal when I spun it by hand, so I passed it off to Jason Burton of NWCustom in Spokane who agreed and had it rebuilt. It had a broken fork, stretched chain, and a gear that looked like a saw blade with sharp, ragged teeth. It seemed we had fixed the problem so I put it all back together and added fresh fluids.
I started it up and it never moved. If I put it all the way into 1 or Reverse it felt like it wanted to load, but ultimately did not. I may or may not have sat in the shop and cried.
So, out it came again much to my joy. Jason once again helped me out by referring me to a transmission man he said I could trust, and he tore it down while I watched. It didn’t take long to find the broken intermediate shaft. Again, shaft was stock. I went ahead and mailed the torque converter out to be opened and cleaned so I couldn’t regret NOT doing it. Everything else in the transmission looked EXCELLENT, clutches and all.
My theory is as follows: I believe that the transfer case was to blame, that it slipped (maybe because of the corner, maybe not) and when it fully re-engaged it shock loaded the intermediate shaft enough to snap it.
I wanted to share this to get any thoughts you folks might have, and also as a cautionary tale for anyone who’s having a mystery issue that could be transfer case-related.
