Got a 460 that was rebuilt by them that has a vibration that is quite noticeable,I did not have them do it but the previous owner of the truck that the motor and trans came out of did. I pulled the motor and trans from the donor truck and into mine and have not taken anything apart on it,the more I think about it I think I felt the vibration in the donor truck on the way home but thought it was the crappy tires and thought it was the same with my truck but now think its been the motor the whole time. What I need to know is I have heard stories about that company where they bore cylinders different sizes and the crank journals could be turned different too so has anyone ever experienced that with that companies motors,I think the motor will have to come out and apart to see what is going on and could also be the torque converter and which they rebuilt the trans too.
I have heard bad things about them as well and some folks love them a friend of mines Jasper 350 vibrated and the keyway for the balancer sheared. the keyway slot was bad/threads gave up installer error? don't know flexplate would be another place to check
Be very careful.. The things you have heard are all true.. Jasper tends to use all of their cores and the result is components that are "odd ball" sizes or sizes that are not available to the public. Like -.060" undersize bearings or oversized OD and undersized ID bearings on the same shaft. The 460 has several different balance combinations, depending on the year of the block/crank core. You may have just the wrong balancer or flywheel on it.
My suggestion would be to approach diagnosing the problem as though you had no knowledge of it's history...and for the most part you don't. What I mean is, look for the problem itself without worrying up front if "Jasper caused it" and trying to prove they are at fault.. Maybe they did, maybe they didn't........Either way, it has to be fixed and there is no warranty. Just for the record, I have no axe to grind for or against Jasper, last one I had was 50+ years ago. Ray
off subject, kinda just freshened up a Fred Jones rebuild from 89 every thing looked great, and had quality parts in it
I know the balance changed in 79 to external so I checked and it does have a 78 and older flywheel with no balance weight and a balancer with a 70 part number so they should be good,I am wondering if it got assembled with a 79 and newer crank but to check that the pan will have to be dropped or the motor pulled.
I can try another balancer and maybe time to drop the pan to see if I can find out what crank is in it.
I had a Jasper motor {2.3 motor} in a small G.M.C. blazer I owned a while back. I never had a problem with it. I Guess I got lucky. Bruce.
I've bought one or two. Just had to replace main seal on a 300 as it evidently had been on the shelf a long time. You can identify crank by '71 and up have a 1.375 pilot deep in the crank flange, and pre '71 have the 1.848 shallow pilot size.
That's one interpretation. Another is, they surely must be doing things well enough most of the time to have been in continuous business for many decades. Ray
with the Jasper motors I think a lot of it depends on the core itself and the person or people putting it together. I worked at an independent shop for years that used a lot of Jasper motors. Some were great, some were ok, and some knocked right out if the crate. we never cared too much because jasper paid the labor if we needed to yank it back out and swap it. the weirdest one was a 350 chevy in a late 90's 1/2 ton suburban. Put it in and ran great, had 60 PSI oil pressure at idle. put it in gear began driving it out of the shop when the oil pressure guage spiked and topped out, I think it was 80psi, no idea how much pressure it was making at that point. I then heard a loud POP and before I could reach the key to shut it off the oil pressure had dropped back to 0. The loud POP was the oil filter case shooting off the motor, which pumped all the oil out in like 10 seconds. Jasper sent us a new motor for that one too...
The vibration could be related to whoever installed it originally but looks like it might have to come apart to find out the cause,I wish I could take the bolts out of the torque converter and separate it from the motor to see if that is a cause but no Fords have studs.
Does vibrate in park/neutral as you brings the RPM's up? If you're sure it's not a miss, then either engine or tranny has to come out, but could you pull the tranny and bolt a bellhousing onto the engine, mount a starter and fire it up to isolate it?
It vibrates in park,I have been told that it could have a early crank that has a larger pilot hole with a later torque converter that needs the smaller pilot hole so it looks like it will have to come apart.
I am thinking it might have a pre 71 crank,going to pull the trans after I put a scope up the drain plug to see if I can get a crank casting number.
Not enough room to slide the trans back so it will have to come completely out,I am thinking about pulling the motor and if it has the larger pilot hole it will get a correct crank. This thing has been vibrating since the PO put it togather and with over 20,000 miles all that vibration can not have done that motor any good,I have noticed the oil pressure is lower so a crank and new bearings might do some good.
I have had bad luck with a Jasper rebuilt engine in a off topic Ford pickup,I used them because I was pressed for time and unable to take the time away from my job to replace rebuild and replace the engine. It ran fine until the warranty was u and within 2 months I had water in the oil,I was hoping it was a intake leak or a blown head gasket,no such luck ,a cracked block.HRP
The local pull and pay has a mid 70s Lincoln with a 460 and going to look it over next weekend,if it looks like it has been taken care of I might grab it.
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