04 LLY 4x4 ex cab sb. 160k on clock. Came in for a broken rear tranny adapter. Long story short is tcase had no pump rub hole. When I initially pulled it apart I drained the case and only got about a cup of black fluid out of it. Fearing the worst I split the case to see what was bad(not my first case rebuild). Much to my surprise only damaged parts I found were a broken range shift fork pad and a spun tail bushing which I beleive had something to do with the tranny adapter cracking. So I did a gmax kit with a PPE conv and put the new parts in tcase along with a MA pump rub kit. Note: this truck is a mess....rear u joints bad, front ball joints bad, rear tires shot with half tread fronts, cluster doesn't work,.....you get the idea. Got it put back together and everything goes fine except for shifting tcase into 4x4 it grinds just a little and then slams into 4x4 when the truck is moving. Sitting still the 4x4 will engage quietly no pops or bangs. It stays in 4x4 no popping in and out even under slight boost launch. So immediately I'm thinking syncro in tcase is fried but to quench my curiosity I drained the front diff to find it a qt low on fluid and gray/black color with glitter in it! So I filled it back up with clean oil and now still same thing only not quite as bad as before. How do I diagnose what is bad without wasting my time pulling a tcase back out that isn't damaged? Btw owner put new tires on it for me because I thought the tire diameter difference may have affected the shifting of the tcase. Is the front diff supposed to couple first to get the driveshaft spinning so the tcase can mesh better or does the tcase shift at same time the front diff does? Thanks in advance!
LLY: 4x4 guru's needed please.
- Thread starter BigDMax05
- Start date
The T case shifts first, utilizing the synchro to get the front driveshaft spinning to vehicle speed. Once it sees the 4x4 shift fork is fully engaged the front actuator engages.
My truck did this as well. Replacing the synchro fixed it.
My truck did this as well. Replacing the synchro fixed it.
So after I got the tcase pulled, disassembled, new syncro in, putting it back together I notice that there is way to much tailshaft end play after the snap ring is on the tailshaft bearing. Closer look reveals that the snap ring groove is worn so badly that 2 snap rings could fit in the groove. Obviously this is a problem because the tailshaft is allowed to slide forward closer to the mode slider which will try to engage first before picking up the syncro. Put a new rear case half on it and back in the truck and going good as new.
The bad u joints is what cracked the extension housing. I would recommend replacing them IMMEDIATELY.
When the rear bushing goes out, it allowed the yoke to flex up and down. I happened to be changing my oil one day and found my bushing out. Sure enough the next day I started getting c0055 codes and speedo was going crazy. If the rear bushing spins out, you HAVE to put a new rear case in anyones. Updated alum ones are about $140 on ebay. I bought that and a rebuild kit off their for about $95shipped and rebuilt mine.
When the rear bushing goes out, it allowed the yoke to flex up and down. I happened to be changing my oil one day and found my bushing out. Sure enough the next day I started getting c0055 codes and speedo was going crazy. If the rear bushing spins out, you HAVE to put a new rear case in anyones. Updated alum ones are about $140 on ebay. I bought that and a rebuild kit off their for about $95shipped and rebuilt mine.