Hi all
First, thanks for everyone's posts, and apologies right up front for the wall of text below.
Backstory: I had a '77 FJ40 rustbucket that had no business being on (or off) the road when I was 18. I sold it because poor. Always wanted another but watched sadly as their values spiraled far out of my reach. Consoled myself with a small collection of geriatric rigs that need lots of work. Then I found a '73 FJ in February that was in super solid shape but had a blown motor and a reasonable price.
I've been working on a transplant drivetrain ever since. This is the first question that I've had that I haven't been able to find a clear answer to so far.
However, the more I read up on this, the more confused I get, so here I am, hat in hand, asking y'all to throw me a line.
Patient: 1973 FJ40 with a 3speed and blown motor. Came pretty complete but fairly well disassembled (seized block in the back, intake and exhaust manifolds, and a bunch of other parts in boxes etc.).
Donor: 1978 FJ40 rust bucket with bad frame, bad body, but running, driving, healthy 2F, 4 speed and transfer case. Someone did a s*** load of mechanical work to this thing but studiously ignored the very real structural issues.
In concept the project seemed pretty simple: Yank the 2f, transmission and transfer case and drop 'em in the '73. Optimism springs eternal 'round here...
I set about it: Pulled the driveline out of the '78, did a refresh (all new seals, checked compression, new water pump, gaskets, oil seal, fuel pump, lines, starter, clutch, etc. etc.). Swapped the dizzy from the '73, cleaned up the thermostat housing and oil filter bracket/ mount, cleaned it all up, painted the block, put the '73 intake and exhaust manifold on in place of the long tube header that would have sounded awesome, but also sounded like it would be a pain in the ass to fit with the throttle linkage etc..
Now it's almost ready to go in, and I'm noticing difference that were less apparent when I was taking everything apart.
First, the driveshafts were the wrong length. No biggie... cleaned, sanded, painted them, GTG right?
Well you all know that's not the case, and now so do I: The bolts are different sizes between the '78 and the '73. Because of course they are.
I had already swapped the parking brake assembly because the one from the '73 was in good shape and the one from the '78 was Napoleon (blownapart).
Whoops, no had to refinish the drum from the '78 because the bolts didn't mate up to the driveshafts from the '78.
Which of course don't mate up to the flanges on the front or rear differentials due to the bold sizes.
Which brings me to my question: The hack mechanic in me wants to simply drill the damned flanges out for the larger bolts. But I suspect there are other complications waiting in the wings here...
I did a bunch of reading and googling, and I don't see anything like a consensus on the 'right' way to do what I'm doing. I know I've addressed the exhaust and throttle linkage issue. I know I have to build a bracket for and fab a clutch line since the slave cylinder and fork are on the driver's side, but the '78 has them on the passenger side.
What other fun and adventure do I need to be thinking about?
Most importantly, am I an a**hole if I simply drill the flanges out to mate up to the newer driveshafts? Or should I put spacers in them and reduce the holes down (seems like a bad idea that will eventually result in vibration and/or falling apart at the worst possible time)? Or bite the bullet and buy new driveshafts with the right flanges on them (ouch)?
Thanks for reading!
First, thanks for everyone's posts, and apologies right up front for the wall of text below.
Backstory: I had a '77 FJ40 rustbucket that had no business being on (or off) the road when I was 18. I sold it because poor. Always wanted another but watched sadly as their values spiraled far out of my reach. Consoled myself with a small collection of geriatric rigs that need lots of work. Then I found a '73 FJ in February that was in super solid shape but had a blown motor and a reasonable price.
I've been working on a transplant drivetrain ever since. This is the first question that I've had that I haven't been able to find a clear answer to so far.
However, the more I read up on this, the more confused I get, so here I am, hat in hand, asking y'all to throw me a line.
Patient: 1973 FJ40 with a 3speed and blown motor. Came pretty complete but fairly well disassembled (seized block in the back, intake and exhaust manifolds, and a bunch of other parts in boxes etc.).
Donor: 1978 FJ40 rust bucket with bad frame, bad body, but running, driving, healthy 2F, 4 speed and transfer case. Someone did a s*** load of mechanical work to this thing but studiously ignored the very real structural issues.
In concept the project seemed pretty simple: Yank the 2f, transmission and transfer case and drop 'em in the '73. Optimism springs eternal 'round here...
I set about it: Pulled the driveline out of the '78, did a refresh (all new seals, checked compression, new water pump, gaskets, oil seal, fuel pump, lines, starter, clutch, etc. etc.). Swapped the dizzy from the '73, cleaned up the thermostat housing and oil filter bracket/ mount, cleaned it all up, painted the block, put the '73 intake and exhaust manifold on in place of the long tube header that would have sounded awesome, but also sounded like it would be a pain in the ass to fit with the throttle linkage etc..
Now it's almost ready to go in, and I'm noticing difference that were less apparent when I was taking everything apart.
First, the driveshafts were the wrong length. No biggie... cleaned, sanded, painted them, GTG right?
Well you all know that's not the case, and now so do I: The bolts are different sizes between the '78 and the '73. Because of course they are.
I had already swapped the parking brake assembly because the one from the '73 was in good shape and the one from the '78 was Napoleon (blownapart).
Whoops, no had to refinish the drum from the '78 because the bolts didn't mate up to the driveshafts from the '78.
Which of course don't mate up to the flanges on the front or rear differentials due to the bold sizes.
Which brings me to my question: The hack mechanic in me wants to simply drill the damned flanges out for the larger bolts. But I suspect there are other complications waiting in the wings here...
I did a bunch of reading and googling, and I don't see anything like a consensus on the 'right' way to do what I'm doing. I know I've addressed the exhaust and throttle linkage issue. I know I have to build a bracket for and fab a clutch line since the slave cylinder and fork are on the driver's side, but the '78 has them on the passenger side.
What other fun and adventure do I need to be thinking about?
Most importantly, am I an a**hole if I simply drill the flanges out to mate up to the newer driveshafts? Or should I put spacers in them and reduce the holes down (seems like a bad idea that will eventually result in vibration and/or falling apart at the worst possible time)? Or bite the bullet and buy new driveshafts with the right flanges on them (ouch)?
Thanks for reading!
