mat in tn Posted January 21, 2022 Share Posted January 21, 2022 i figured i would open up a discussion to the panel of experts and novices alike. one of the most common things I end up doing is "problem solving". been doing it for years. sometimes it's more like hunting season though where you try everything yet never get a sight of your quarry. we just finished an install on my friends 94 f150 4wd. it's a truck he has been driving hard along with teaching both kids to drive and frankly it's a real testament to "built ford tough"! Anyway, he rebuilt a 5.8 to replace a 5.8. and it runs and he has been driving it, but it has a "shake". idle to about 1200. bad enough that its now leaking from the rear main. now before anyone yells at me. haha. I know these don't heal! not my truck, not my build. just thinking over a diagnosis and willing to help him. I have been theorizing on my own about possible causes. harmonic balancer, flex plate etc. new balancer but original flex plate. Replaced transmission a year ago. third one! the second was only in doing 4wd conversion. originally a 2wd truck. it happens at idle in neutral also so to me that removes all but the torque converter/flex plate. how common is torque converter balance problem with an e4od? just because I have not dealt with it does not mean others haven't. again, I'm looking for other experiences and opinions. any item which spins must be balanced and the more you bolt together the more you must balance the whole assembly. Link to comment Share on other sites More sharing options...
grumpin Posted January 21, 2022 Share Posted January 21, 2022 My 92 Bronco is a 5.8 and E4OD. I had an E4OD behind a 460. Never had them apart, no vibes or shaking. Because it was rebuilt the first thing that popped into my head was a bad lifter, sticky, stuck, collapsed. You would have heard it ticking if it was collapsed. Or a stuck valve. If it wasn’t shaking before the rebuild and is now, I would assume it’s the engine. Harmonic balancer as you mentioned. I may be off base, but what I thought of. Link to comment Share on other sites More sharing options...
mat in tn Posted January 21, 2022 Author Share Posted January 21, 2022 My 92 Bronco is a 5.8 and E4OD. I had an E4OD behind a 460. Never had them apart, no vibes or shaking. Because it was rebuilt the first thing that popped into my head was a bad lifter, sticky, stuck, collapsed. You would have heard it ticking if it was collapsed. Or a stuck valve. If it wasn’t shaking before the rebuild and is now, I would assume it’s the engine. Harmonic balancer as you mentioned. I may be off base, but what I thought of. after talking this over he says it's been shaking for a long time but it's much worse now since changing engines. I could not get him nailed down on whether it has been happening since the latest trans was installed or whether it is the original torque converter. but I'm trying to diagnose rather than just deciding. I believe it has been replaced but not sure Link to comment Share on other sites More sharing options...
mat in tn Posted January 21, 2022 Author Share Posted January 21, 2022 after talking this over he says it's been shaking for a long time but it's much worse now since changing engines. I could not get him nailed down on whether it has been happening since the latest trans was installed or whether it is the original torque converter. but I'm trying to diagnose rather than just deciding. I believe it has been replaced but not sure one more thing. we did run the engine for quite some time on an engine run stand. up to temp a few times tuning and timing etc. no indication of any vibration etc . and solid mounts. should have been even more noticeable that way. run without torque converter on run stand. Link to comment Share on other sites More sharing options...
grumpin Posted January 21, 2022 Share Posted January 21, 2022 one more thing. we did run the engine for quite some time on an engine run stand. up to temp a few times tuning and timing etc. no indication of any vibration etc . and solid mounts. should have been even more noticeable that way. run without torque converter on run stand. Oh, ok. Motor mounts, tranny mount? Link to comment Share on other sites More sharing options...
mat in tn Posted January 21, 2022 Author Share Posted January 21, 2022 Oh, ok. Motor mounts, tranny mount? all mounts good and even replaced the transmission mount in the process to be sure Link to comment Share on other sites More sharing options...
grumpin Posted January 21, 2022 Share Posted January 21, 2022 all mounts good and even replaced the transmission mount in the process to be sure This will drive a person nuts! Link to comment Share on other sites More sharing options...
mat in tn Posted January 21, 2022 Author Share Posted January 21, 2022 This will drive a person nuts! oh he is there! haha Link to comment Share on other sites More sharing options...
1986F150Six Posted January 22, 2022 Share Posted January 22, 2022 oh he is there! haha Did you confirm that the torque convertor had been replaced? Link to comment Share on other sites More sharing options...
grumpin Posted January 22, 2022 Share Posted January 22, 2022 Did you confirm that the torque convertor had been replaced? Since things around the motor have been checked. Maybe the driveshaft or rear end. Wheel bearings. Brakes. Link to comment Share on other sites More sharing options...
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