crank problems on 85R

[jr66645]

Has anyone had any problems with a hotrod crank and bearings? The crank seems to be tapered so the bearings won't fit flush without quite a bit of effort. So every time I get the case halves flush with one another the crank is binding and so is the transmission on my 85R. When I split the case it came apart very easily and now it's a trailprotrailprotrailprotrailprotrailpro to get it back together. Any information would be much appreciated. Thanks boys.

[jr66645]

You're talking crankshaft bearings as in the ones that press into the cases correct? It sounds like they aren't properly seated in the cases. How did you install them? In the cases and then on the crank, or onto the crank and then tried to put the cases over the bearings? Heat? Cold? Pressure? Tell us everything.

Oh, and this needs to go to Bikersville, no 2 wheelers here.

Yea the crank bearings. I installed them in the case with heat in the case and cold bearings. I have a feeling that they are not seated all the way myself. At the time that I installed them I didn't have access to a press so I tapped them in on the outer race with a hammer. I split the case again today and now I'm having a hard time getting the crank back out of the clutch side.

By the way I ain't talking about no CR. Most of the time I am riding a 2 wheeler only because the 3rd tire is in the air.

:)

[Mosh]

It is the Hot rods crank. They always suck to install. The tolerance for the bearing fit is way off vs. the OEM crank. The journals are too fat on the Hot rods, to fit into the bearings properly. IDK why the hell they have not fixed the issue yet. They have been that way for years. You need to machine the crank journals down. They should still have interference fit, so take the bearings and crank to a machine shop and have them turn the journals down to fit the bearings properly.

[Dirtcrasher]

Ugly lesson learned!!

[ONEBAD350X]

The OEM Honda TRX, ATC crank, is a slip fit on the clutch side, regardless of the bearing type.
Now the Hot Rods cranks, they are press fit on both sides, into both main bearings.

[barnett468]

Hello;


Please explain step by step EXACTLY how you are installing the crank into one half and installing the other case half.

Are the cases going together completely?

Which case half are you installing the crank and gears in?

What EXACTLY do you mean by “the crank is binding.”?

What EXACTLY do you mean by “the transmission is binding.”?

The crank has nothing to do with the transmission, therefore, if the trans is binding it is a separate/unrelated problem and the cause needs to be determined.

The transmission should be in neutral during the assembly.

From what you’re saying, I’m “guessing“ that you are installing the crank and trans into one case half then pushing the other case half down by hand and then possibly using the case screws to pull it together the rest of the way after which things are “binding”. Is this correct?

If your cases are coming together or almost together with little effort it is unlikely that your bearings are too tight on the crank.

It is also possible but highly unlikely, that your crank bearing journals are tapered. It is also unlikely but possible that the radius on the journal at the crank is too large therefore prohibiting the bearing from going on far enough.

All this being said, imo [as if should matter], it would still be a good idea to get the journal dimensions checked as suggested by MOSH along with the radius.

If you are not PULLING the crank into the bearing it is possible this is the cause of the crank feeling like it is binding therefore you might make a tool like the one shown in the manual to try this with. This can be made with the proper size of metal pipe, around 1/4" thick fender type washer and a grade 8 bolt with a bunch of grade 8 washers to use as spacers under the bolt as needed because the bolt might bottom out in the crank.

If you cannot see if the bearings are all the way in the case it might be best to remove them, measure their thickness and the depth of the bearing hole in the case so you have a reference point and install them again.

To install the bearings into the case, I would put the bearing in the freezer for around 45 minutes, heat the case in the oven at around 180 for around 10 minutes prior to removing the bearing from the freezer then put some oil on the bearing and drop it in with a pair of gloves. It might require some light tapping but I highly doubt it.Use oil on the bearing and crank journal for assembly.

If you place a socket upside down on the inner or outer bearing race then place something moderately heavy on it [a 3 lb hammar], this will prevent the bearing from lifting at all while the case cools.


The manual says to install the bearings in the case first.

Honda implies the crank should be a slip fit in the LEFT side and that on occasion, the crank may need to be “pulled” Into the right side bearing using the tool mentioned and shown on page 8-15 in the orig manual in the link below. This sounds a bit bizarre to me but it is what it is.

The manual might take up to 7 minutes to load.

http://www.oscarmayer.net/atc/manuals/honda/atc250r_85-86_servicemanual.pdf

[DohcBikes]

Hello;


Please explain step by step EXACTLY how you are installing the crank into one half and installing the other case half.

Are the cases going together completely?

Which case half are you installing the crank and gears in?

What EXACTLY do you mean by “the crank is binding.”?

What EXACTLY do you mean by “the transmission is binding.”?

The crank has nothing to do with the transmission, therefore, if the trans is binding it is a separate/unrelated problem and the cause needs to be determined.

The transmission should be in neutral during the assembly.

From what you’re saying, I’m “guessing“ that you are installing the crank and trans into one case half then pushing the other case half down by hand and then possibly using the case screws to pull it together the rest of the way after which things are “binding”. Is this correct?

If your cases are coming together or almost together with little effort it is unlikely that your bearings are too tight on the crank.

It is also possible but highly unlikely, that your crank bearing journals are tapered. It is also unlikely but possible that the radius on the journal at the crank is too large therefore prohibiting the bearing from going on far enough.

All this being said, imo [as if should matter], it would still be a good idea to get the journal dimensions checked as suggested by MOSH along with the radius.

If you are not PULLING the crank into the bearing it is possible this is the cause of the crank feeling like it is binding therefore you might make a tool like the one shown in the manual to try this with. This can be made with the proper size of metal pipe, around 1/4" thick fender type washer and a grade 8 bolt with a bunch of grade 8 washers to use as spacers under the bolt as needed because the bolt might bottom out in the crank.

If you cannot see if the bearings are all the way in the case it might be best to remove them, measure their thickness and the depth of the bearing hole in the case so you have a reference point and install them again.

To install the bearings into the case, I would put the bearing in the freezer for around 45 minutes, heat the case in the oven at around 180 for around 10 minutes prior to removing the bearing from the freezer then put some oil on the bearing and drop it in with a pair of gloves. It might require some light tapping but I highly doubt it.Use oil on the bearing and crank journal for assembly.

If you place a socket upside down on the inner or outer bearing race then place something moderately heavy on it [a 3 lb hammar], this will prevent the bearing from lifting at all while the case cools.


The manual says to install the bearings in the case first.

Honda implies the crank should be a slip fit in the LEFT side and that on occasion, the crank may need to be “pulled” Into the right side bearing using the tool mentioned and shown on page 8-15 in the orig manual in the link below. This sounds a bit bizarre to me but it is what it is.

The manual might take up to 7 minutes to load.

http://www.oscarmayer.net/atc/manuals/honda/atc250r_85-86_servicemanual.pdfWhile this info is not HotRods crank specific, just wanted to say thanks for taking the time to give some great tips on crank installation, especially in a "crank installation issues" thread.

[RoscoW]

BDT sells OEM bearings that are honed on the ID for a OEM type "slip fit " on Hot Rods cranks. Cost is a bit more than OEM but a squeeze with your hands will seat the cases together.

Ross..

[Mosh]

BDT sells OEM bearings that are honed on the ID for a OEM type "slip fit " on Hot Rods cranks. Cost is a bit more than OEM but a squeeze with your hands will seat the cases together.

Ross..That is a good point. I thought I remember reading that somewhere.
I still suggest the crank be machined and trued. The large webs are still very thick and heavier than stock and there is video floating on youtube of a builder showing the hot rods cranks being out of true some .005 to .008 thousandths or something considerable enough to cause excess vibration and premature bearing wear.

[Billy Golightly]

I had one hot rod crank I actually had to machine down the stator side bearing surface a couple thousandths before it would fit in the bearing without acting like it was going to break its way out of the case when trying to press it back together. Your mileage may vary

[250rRoostmaster]

Never had an issue with my hot rods +4 crank. I used OEM bearings and everything slid together real nice. Granted i did have the crank trued/welded by my engine builder which may have helped. Freezing the crank helps with install as well..

[Mosh]

I want to verify a couple quick points.

Most importantly I fully endorse Wiseco products and Hot Rods cranks. I appreciate their willingness to continue parts support for Atv riders. As with anything aftermarket they require extra set-up to use but for me it has never been anything that a competent mechanic can not overcome. So Thanks to Wiseco for your support.

[250rRoostmaster]

I will also add that my crank was the yellow box crank which are the newer style cranks. I've researched this a bit and the older cranks that came in the red and white boxes seemed to have a lot more problems then the newer yellow box cranks.

[Mrs.Mosh]

jr66645, I hope you found some good info and the answers to your questions.





EDIT: I cleaned this thread up...lets stick to the topic before bans are issued.

[jr66645]

Thanks for all the help everyone. I really appreciate it. I bought a press and got it together last night.