Help with my other project - FJ40 rebuild

Scott R · Scott R's Garage

Long story short, I've been doing a three year frame off rebuild on a 72' Landcruiser FJ40, including a 87 350TBI conversion, power steering and disc brakes, 4 speed transmission. I suppose I could have been done sooner but the engine rebuild on my SC has been sapping my time this winter. So I figure Pelican probably has more combined engine experience than almost anywhere, maybe one of you guys knows what's up.

I installed the engine and drive line when the frame was finished two years ago. It's as I said a 75 350TBI with an AA bell housing, 4 speed transmission with a special output shaft that mates to the 72 three speed t-case that came with this 72 FJ40.

When I first installed all of this we did a functional test of the drive train by turning over the engine with an impact gun and walking the gears and testing the clutch, all was well at that time. Fast forward two years to yesterday and I'm completing the Saginaw power steering conversion, in fact I'm installing the belt on the pump and I wanted to move the engine to help slip the belt on. To my surprise it's stuck!

This gets better, I can crank the engine back about 90 deg no problem, then forward 90 deg, and "CLUNK" it's stuck! It won't go more than 90 deg in either direction, clutch in, clutch out, transmission in neutral. I don't know what happened between then and today, and I'm at a bit of a loss. Before I pull the engine again, does anyone have any thoughts on this?

Tim Hancock · 02-19-2007, 10:06 AM

Don't know, but turning the engine over with an impact gun sounds kind of scary. Are you sure your power steering pump is not the culprit?

Scott R · Scott R's Garage

Quote:

Originally posted by Tim Hancock
Don't know, but turning the engine over with an impact gun sounds kind of scary. Are you sure your power steering pump is not the culprit?

Yes, first thing I pulled off was the pump, thinking I would start work backwards logicaly. As far as the impact gun is concerned I was thinking it was about the same as using the starter, which I felt would burn out if I ran that sort of test with it.

notfarnow · 02-19-2007, 10:13 AM

Tim makes a good point... are all the "belt" accessories disconnected? Are you sure it's an internal issue?

Have you posted over at http://forum.ih8mud.com/ ?

Jeff Higgins · 11:48 AM

Stuck valve? Broken timing chain or stripped cam gear (I think they have plastic teeth)? Pull the valve covers and see if they all open and close. The "rat-a-tat-tat" of that impact gun might have done something to the timing chain. Unlike turning it over by hand now, it probably has enough oomph to keep turning past valves hitting pistons. That would make it very ugly inside that 350. Hopefully it's something more innocuous than that.

Scott R · Scott R's Garage

Quote:

Originally posted by Jeff Higgins
Stuck valve? Broken timing chain or stripped cam gear (I think they have plastic teeth)? Pull the valve covers and see if they all open and close. The "rat-a-tat-tat" of that impact gun might have done something to the timing chain. Unlike turning it over by hand now, it probably has enough oomph to keep turning past valves hitting pistons. That would make it very ugly inside that 350. Hopefully it's something more innocuous than that.

Excellent suggestion, I'm forgetting that I'm dealing with a single large timing chain here. I'll pull the valve covers off tonight after I get home. And honestly if the engine is shot, I'll part this thing out, it was left to me by my brother before he disappeared. It's been sitting in my garage for years and the wife wants it out.