Gq diesel rebuild --- she's still locked!

[shakes]

Recently bent a rod in a GQ ute with the later model jap spec diesel in her. (she breathed in water while idling)

removed all rods and pistons and the crank spins nice and freely in the mains.

Replaced the only visibly bent rod, a piston which had signs of detonation on top,(both in bores 3 & 4) rings and rod bearings in all.

a slight clean up of the bores with a stone surfacing tool and no lips of irregulaity's could be seen or felt. all pistons and rods slid in nice.

with no head on the starter will only kick it enough just to nudge each piston not even 5mm (please dont start lecturing me on that one)

we're gunna nudge out each piston and rod today one by one and hope we can elimanate which one is holding it....fingers crossed that all we have is another bent rod. but unfortunatly its looking like the crank.

Can anyone shed some light on any other possibilty's on why she isnt turning with all the rods and pistons in. Budget is a fair sized issue

Thanks in advance

Simon

[GutSquisher Media]

It's possilbe you have a bent crank shaft, it may not be a visual bend but when you bolt everything inplace it binds.

[J Top]

Loosen of the big end caps one at a time till she spins.
At a guess the crank is free with no c/rods so it should be fine.
The likely scenarios are,
incorrect cap on the replacement rod
mixed caps between rods
incorrect size big end brgs, plastigage?
in gear
flat battery
J Top

[shakes]

yea she's the crank alright, unbolted all but the 2 end mains caps and she spins, you can see the oil smearing on one side and not the other can also feel the tight spot when turning it by hand.... clearances beside the rods where the crank was bent was 0!!! compared to .15 at the other end of the motor

Next question!

I've had confilicting advice from different suppliers and nissan is shut for the night so i cant confirm. any links to other sources?

One place said a TD42 crank is a TD42 crank (they quoted $550)
Another said they were different (quoted $1350) Its the later model '96? GQst jap engine with the flat tops So I'm Leaning to the latter but price wants me to swing the other way

who's right?

[GutSquisher Media]

It may not be as bad as it sounds, take your crank to an engine rebiulder and get it checked. If the bend is not to large a regrind to smaller journals and a balance job may recover the crank.

If not try to buy a TD42 short block from a wreaker. and use it for a rebuild job.

[Woop]

Make sure there is no debris trapped between the bearing and the block--it only needs a small amount cause problems when re-installing bearings. When i re-built my TD42, the shop ground my crank for a main bearing to crank journal clearance of 0.050mm. The crank MAY be able to be re-ground and balanced.

Also you may need to have the new rod cap line bored to achieve the correct bearing clearance.. The original NDC mains and big-ends are available much cheaper from:

M.D Spares
4 Horsecroft Pl
Moorabbin
95530388

Nick

[BIG GQ]

To the best of my knowledge a TD42 crank is a TD42 crank. No difference. The likes of Bazzle, Wendel, etc. will confirm this though.

[shakes]

Cheers thanks for your help and quick responses.... Woop i`ve seen the damage debris in parts when re-assembling can cause IE a snapped crankshaft, wasnt the most fun i`ve had in a car! thankfully it was OHC and only took us around 2hrs of running around to have her running again

I'll give those guys you suggested a call later.