Author Topic: Crank play (Read 10781 times)

JoePA · « **on:** July 23, 2013, 09:37:26 PM »

My engine started making a wierd noise earlier in the season. Didn't think much of it at the time but it only is getting worse. So, tonight I decided to do some investigating. I checked my counterbalancer and found one of the ears broke off on the bearing holder when I pulled the stator cover. OK no biggie that must have been it. But I figured I would check everything while I was at it. I grabbed the flywheel and went to try to move it and noticed i had side to side movement, quite a bit. So I pulled the clutch cover to make sure nothing came loose and all good under there.

My question is why the side to side movement? I replaced the crank and new bearings two years ago with a Hotrods crank and cr500 bearings. Could it be the bearings are shot already? I did have a head gasket go and burned up some antifreeze but not a lot. Any other ideas?

rsss396 · « **Reply #1 on:** July 23, 2013, 11:18:18 PM »

This seams odd like maybe the bearings are slip fit on the crank or hopefully not the bearings loose in the cases.

The crank bearing would have to have allot of wear to make much movement I would think

Polonda · « **Reply #2 on:** July 24, 2013, 12:05:18 AM »

Wouldn't it have to be the bearings loose in the cases? Unless the bearings are very worn? On the right side the the bolt that goes into the end of the crank pulls the crank, bearing, sleeve, and primary gear all together correct? This should leave no side to side play unless the bearings are moving?

Trying to picture this in my head. I could be totally wrong......been a while since I was in my cases.

fearlessfred · « **Reply #3 on:** July 24, 2013, 02:00:52 AM »

there is a very slight amount of horizontal movement

JoePA · « **Reply #4 on:** July 24, 2013, 07:24:32 AM »

I'm going to tear into it tonight. there is about 3mm of movement. and I think the problem is I have the machined inner race bearings and that is allowing it to move. It may the cases are worn as well but won't know till I dig.

rsss396 · « **Reply #5 on:** July 24, 2013, 08:49:34 AM »

I like 1 bearing machined for a tight slip fit and 1 normal tight fit bearing that way the crank does not float side to side but does allow for the crank halves to seek its own center with no bind.

I normally put the tight bearing on the transmission side and let the stator side float

JoePA · « **Reply #6 on:** July 24, 2013, 09:17:21 AM »

This must be where my issue is as I have two floaters in there!! That didnt sound right! LOL I'm going to spilt the cases tonight and see if thats the issue. Once agian thank you for the excellent input.

fearlessfred · « **Reply #7 on:** July 24, 2013, 02:05:13 PM »

joe ,I saw on the other site were both bearings are machined different sizes for the larger hotrod crank journals.is it possible that the larger i.d. bearing is on the stater side.never messed with a hotrod crank ,so I really don't know

JoePA · « **Reply #8 on:** July 24, 2013, 02:59:56 PM »

Yes, I wasn't sure why they were machined but then I was reminded why. I think either the bearings are bad or the cases are shot. Now that i think of it, Why would the HotRods crank be larger than OEM? It was my first crank replacement at the time so I think thats why I went with those bearings. Frustrating when you sink a bunch of money into it so it will last then only get two years out of it unless its the cases then thats understandable as they have 20+ years on them.

rsss396 · « **Reply #9 on:** July 24, 2013, 03:07:55 PM »

for some reason hot rods cranks have a hair bigger O.D. on the bearing shoulder of the crank, I thought BDT sized those so they were still a slight press fit like the OEM are, maybe they were sized wrong?

JoePA · « **Reply #10 on:** July 24, 2013, 03:18:34 PM »

I think they might have been sized wrong cuz those case halves slid together like butter. I'll know tonight when i get them split.

BJR88250r · « **Reply #11 on:** July 24, 2013, 04:32:51 PM »

Keep us posted mine has to side play too. So I'm curious I always thought side to side ok up and down no go. Both 250r's ive owned as of recent have had some side to side play.Thanx

fearlessfred · « **Reply #12 on:** July 24, 2013, 05:51:35 PM »

If I remember correctly side to side is only one thousanth

Polonda · « **Reply #13 on:** July 24, 2013, 07:37:15 PM »

Even if the bearings are slip fit on both sides of the crank the only play you should have left to right is the play in the bearings. Which should be basically nothing. I think your going to find upon inspection that your bearings are loose in the cases. You can use bearing retaining compound for a temp fix it they are not to bad, but it will not last.(tried it on mine) Either replace the cases or have Pete at Hybrid put some sleeves in for you would be my recommendations.

fearlessfred · « **Reply #14 on:** July 24, 2013, 08:28:35 PM »

Even if the bearings are fixed and stationary ,the i.d. on the bearings being to big could allow the crank to slide a little back and forth.I think thiss is why whats his name wants joe to send the bearings back to him