Here's a good one for the techs

[rabbit1]

I recently pulled a '94 4.0 from a parts yard to put into my '88 B II. I got the engine, tranny, dash, steering column, and all associated wiring harnesses. After the rebuild of the motor I noticed a bit of pressure while trying to rotate the crank pully. I didn't think much of it until recently (with the engine installed in the truck) when I tried to turn the crank only to find that it is locked. If I remove the rod bearing caps I can rotate the crank freely. When I tighten the caps I get a little resistance but I can still rotate completely. Here's where it gets tricky. If I don't rotate it for a little while it locks up and I have to loosen the bearing caps to free it up. I did replace the rod bearings and rings and I used assembly lube on the new ones. I tightened the cap nuts to about 24 lb/ft. I have not put oil in the pan yet because I have to drop it every time it siezes up. Has anyone experienced this before? All of the parts seem to move and slide like they should before I assemble everything, but after assembly it all locks up. :scratch:

 

[rabbit1]

Wiring issue

In my B II 2.9 to 4.0 swap I used a 94 4.0 and A4ld (4x4) with the wiring harness from that engine. I got a dash and wiring harness from a '94 2wd, and I pulled a steering column from a '91 Ranger. Is there an obvious explanation for the fact that when I turn on the head lights or parking lights, both blinker arrows on the instrument panel light up and the panel is rather dim and the bright lights indicator is illuminated when using low beams and goes out when using high beams? Is this merely a compatibility issue between the '91 steering column and the '94 dash? Oh yeah, also when I turn on a blinker I can hear a relay under the hood in the fuse panel. Any help would be greatly appreciated.

 

[SVO]

Bent crank :scratch:









Jeff - :navajo:

 

[rabbit1]

Bent crank :scratch:

I don't think so . Without the rods connected, it turns smoothly and with the rods connected all of the pistons rise to the same point in relation to the block surface. Thanks for the suggestion though. I'll look ati it again.

 

[Nedwreck]

What are you turning the crank with? Like it's locked tight with a 18 in. bar or just reeeeaaalllllyy tight?

I've built a few that were kinda tight, but if it won't turn it with a torque wrench at spec there's trouble.
I don't remember what i used for 4, 6, or 8 cyls to do that though.

You didn't somehow end up with undersize rod bearings?

Did you plasti-gauge all the bearings?

Ohh... edit.... you used assembly lube... now mebbe I'm old, but we only used that on camshafts. seems like the old style assy. lube was thick thick stuff. I always drenched/washed bearings in oil when assembling. Don't listen to me though.. I haven't built a motor in many years. Times change as do methods.

 

[skoal_mint]

Dont nothing about the that engine, but some rods are offset and seen this same thing happen if one was installed wrong.

Or what happened to me befor is that i nicked the crankshaft with the connectiing rod, and loosend the cap and found it turned easier... LOL, showed everyone "does this seem stiffer then usually??, then i removed the bearing and she was chewed up... always use protection, even when rebuilding a engine

 

[rabbit1]

What are you turning the crank with? Like it's locked tight with a 18 in. bar or just reeeeaaalllllyy tight?

It's kinda like I feel like I'm going to break the pully bolt with a 24" breaker bar. I'm not sure if the rods are offset...I don't think so. the assembly lube is some pretty thick stuff but it's slick as hell. I got the bearings from the local parts house and even went back to verify the part #. Since the crank shaft is about the only thing I didn't mess with for the rebuild I think I may as well go ahead and remove it and have it checked. If that's not it I'm stumped.

 

[Cobraguy]

One of three problems:

(1) Wrong bearings. Check each and every bearing for proper clearance (including the mains). Clean everything prior to measuring and have everything at room temp. Using micrometers is far and away the best way to measure...including the rod bore...but that's not realistic in your case. So use plastigage. For something that's not having the crank turned and rods reconditioned, I like 1.5 to 2.0 on the rods and 2.0 to 3.0 on the mains. Try to stay on the minimum side.

(2) You have a piston/rod in the wrong side. The rod locates the rod bearing off to one side a bit. This is critical. The side of the rod/bearing with the clearance goes against the fillet of the crankshaft. This ABSOLUTELY has to be correct or the reciprocating assy will bind when torqued. (can you move the rod side to side with everything torqued?) Pull a rod and cap and you will see what I mean by the bearing being offset to one side.

(3) You have the rods and caps mixed up. (wrong cap on the rods)

 

[gijoecam]

He beat me to #1 and #2... Hadn't thought of #3... but they're all plausible.

The key, IMHO, is going to be using plastigauge to check the clearances. That'll likely show the problem right away.

 

[Cobraguy]

The key, IMHO, is going to be using plastigauge to check the clearances. That'll likely show the problem right away.

Joe, you could get some very false clearance reading if #2 is the case and your plastigauge doesn't extend entirely across the journal due to only the very edge of the bearing being tightened against the crank fillet. That needs to be visually checked first...then clearances checked.

 

[rabbit1]

Great info guys. I defnately didn't pay attention to those things. I did try to make sure the rods went back in the hole they came out of and faced the same way that they came out but that doesn't mean I didn't mess it up somewhere. I'll definately check it out. I may not even use this engine afterall. A guy at work just offered me a whole (wrecked) 5.0 Explorer for $500 with all good drivetrain. I do have a ? about that one though. It's 2wd. What tranny can I pull the tailshaft from to make it work. I would assume it's not an A4LD. Also, would I have to swap out the computer to work with 4-wd? I know it's probably on the forum but I haven't had a chance to research it yet. Thanks guys.

 

[Mickelsons]

That happened to me one time, i had mixed up 2 of the rod bearing caps, they have to go back on the rods they came off of.

 

[Cobraguy]

When I say the rod/piston is on the wrong side, it could also mean it's installed upside down. (wrong side forward) That will also put the wrong side of the rod against the crank fillet.

You will need an output shaft from a 4R70W. That's all they put behind the 5.0. However, if I were to do this again, I would seriously consider using the Advance Adapter kit that would allow the use of your existing transfer case so you could retain all the factory controls there. (assuming a 4406 swap) It would definitely depend on how I was going to use the car because that case isn't as strong. But I would rather do that than use the factory AWD case.

 

[Four0Sport]

glad to see my quote is still in your sig cobra.., reading this post makes me miss my broncoII, i have one with a blown motor but it is the newer front end, i miss my 88. if i was smart i would have bought my moms old mail delivery bronco, only had a busted heater core and she sold it for $500.

as far as this post goes.. a 5.0 swap is possible but, read 410Fortune's buildup diary, he did the same swap. it goes over all the problems/successes with putting in the small block.

 

[rabbit1]

Ok. I pulled the engine back out and here's what I found. I could not tell if all of the caps are in the right spot as they were not marked. It does appear that they were all installed in the right direction. Upon removing the caps and bearings this is what I foundThe crank has only been turned by hand. The engine has not been run yet. Do these pics possibly narrow it down to a specific issue?)
#1 & 2

#3 & 4

#5 & 6

 

[Cobraguy]

The tangs on the bearings for the caps and rods should always be together on the same side...if that helps. But if you have possibly mixed up the caps and rods, then you have no choice but to start from scratch and have all the rods reconditioned or replaced. There is no way around that. They are a machined set. Next, let's look at what bearings you have there. You are still using a standard sized crank, right? Pull the bearings out of the rods and caps and look at the back of them. See if they say STD, .001, .010, .020, etc. It should be stamped on the back of each and every bearing shell. That sure appears to be undersized bearings for the size of the crank, or that you have rod caps mixed up so the bore diameters in the rod are wrong. If that's the case, then you could have the correct bearings. Regardless, they are shot and you need new ones. This is why it is so very important to check every bore and shaft size if possible. You never know who has stuck what part in a box.

 

[skoal_mint]

Yeah those are cold cracked rods, I hope you are forsure their the right caps on the right rod.

That engine would have been up in smoke in a matter of minutes if you started it, lol

 

[rabbit1]

Thank you guys for all the help:notworthy. It turns out I had the caps on backwards. They are stamped and in the right place but I didn't line up the tangs on the bearings. I turned them around and torqed it back down and it all spins fine. I have new bearings to put in tomorrow. I'm sure glad it wasn't worse.

 

[Cobraguy]

Yeah those are cold cracked rods, I hope you are forsure their the right caps on the right rod.

That engine would have been up in smoke in a matter of minutes if you started it, lol

I don't believe 5.0 rods are cracked. I think they started that with the mod motors.

Glad you found your problem. Now, make darn good and sure you measure EVERYTHING prior to buttoning it up.