lt77 rebuild

[mateusz]

Hi guys ive rebuilt lt77 but when i engage 5th gear the mainshaft gets hard to turn. Any ideas guys?

[DazzaTD5]

5th gear is on the layshaft and is an overdrive, so when you say harder to turn the mainshaft, you mean as in from the bellhousing end (the input side). So it turns less than the output (the transfer case side), yes should be harder to turn.

Within reason...
The nut on the end of the layshaft hasnt been over-tightened? its from memory round 200NM ?? and has a square drive to the oil pump, was the pump all done and free?

My guess though is you dont have enough end float (preload) for the mainshaft, layshaft. On the bellhousing end the oil seal housing (cast plate with 6 bolts), there is selective shims inside it, you need to adjust this thickness to get correct end float (preload), which I have no idea what it is without looking in a manual.

You can test this by loosing off the 6 bolts (allowing the oil seal housing to be free (free it up if you have used sealant)), just crack the bolts off finger tight, then test your shifting, if it feels good, your preload is way too tight.

Any gearbox wizzers, correct any of my info as needed.

Regards
Daz