BX2230 rocker arm nut torque

[gssz]

I've never adjusted valves on anything other than single cylinder generators in the past, but I thought I would be brave and adjust the valves on my recently acquired BX2230 before I do a compression test. I have a shop manual for a BX2200 which seemed to indicate that I need to torque the rocker arm nuts to 20 foot pounds. I got the nuts pretty snug with a 10mm wrench and then I thought I'd get it perfect with a torque wrench and I promptly broke the nut off the exhaust valve rocker arm of the first cylinder. I almost thought that was the actual valve... boy I'm glad it wasn't, as I didn't want to be removing the head.

I have two questions:

1. What is the correct torque for that nut please?
2. Can I buy just the set screw that I broke instead of the whole rocker arm?

Thanks!

 

[D2Cat]

No, you just need the adjusting screw. I think it is part # 15841-14030.

You can see the components at https://apps.kubotausa.com/illustrated-parts/

Just agree at the beginning, then enter your tractor model, then go to engine, then find the valve assembly. See part #160 (I think)

And I'm not a professional mechanic, I tighten them with a box end wrench and make sure they are snug (only using my wrist)!

 

[Fordtech86]

I looked at the bx2200 manual and I think you confused the torque spec for the rocker arm hold down brackets with the adjuster you broke.

 

[gssz]

thanks guys - I edited the post before realizing you already answered. Indeed, what a relief that I don;t have to remove the cylinder head

 

[gssz]

No, you just need the adjusting screw. I think it is part # 15841-14030.

You can see the components at https://apps.kubotausa.com/illustrated-parts/

Just agree at the beginning, then enter your tractor model, then go to engine, then find the valve assembly. See part #160 (I think)

And I'm not a professional mechanic, I tighten them with a box end wrench and make sure they are snug (only using my wrist)!

Thanks! I ordered all six adjusting screws and nuts from Coleman Equipment as I probably stretched three others while I had the engine at TDC.

 

[200mph]

So how much adjustment was necessary?

 

[gssz]

So how much adjustment was necessary?

Not much... about .001" as the .008 feeler gauge was going through pretty easy. I only got through adjusting the first 4 before turning the flywheel 360 degrees for the last two. When I started torquing the nuts it felt like even 15 ft lbs is too much, but it worked on the first nut so I kept going. I added more torque to the other three and when I got back to the exhaust valve on #1, the adjusting screw snapped.

I started by chasing another problem with slow starting (a separate thread), where a couple of guys suggested checking the compression. I already replaced both fuel filters, air filter, glow plugs (made sure they come on when the key is in that position).

So I was adjusting the valves while I am waiting for the Mityvac compression tester, to make sure they are as close to spec as possible in order to get an accurate compression reading.

I still haven't found the torque spec for the adjusting screw nut, so if someone has it, I would love to know what it is.

Should I use the blue locktite on these nuts?

 

[D2Cat]

Do not use any loctite on those nuts. Simply hold the position with a screwdriver and use a box end wrench to snug the nut down. Then double check the clearance.

 

[gssz]

Found something on Kubotabooks.com for 03 series diesel engines, which suggests general torque guidelines for various size bolts. Since this seems like a 6mm screw, it sounds like I should stop at 7 ft lbs!

 

[gssz]

Do not use any loctite on those nuts. Simply hold the position with a screwdriver and use a box end wrench to snug the nut down. Then double check the clearance.

Sounds good - thanks!

 

[D2Cat]

PLEASE NOTE THIS IS NOT A KUBOTA ENGINE. DO NOT USE THE TORQUES LISTED FOR CYLINDER HEAD OR OTHER BOLTS......

I was kind of curious to see if I could find a torque spec for your question. So I did a quick internet search. Someone asked the same question (as yours) about rocker arm torque. See the service manual page I copied, down near the bottom... "tighten the locknut securely after adjustment."

Here's a link to the entire thread if you want to read all the guys comments. https://forum.ih8mud.com/threads/torque-value-valve-adjustment-lock-nut.462486/

 

[beex]

I do my own valve adjustment too, it’s easy. I adjust with a box wench and screwdriver also, so have to go by feel. 20 lbs isn’t much, so it’s best to use a short wrench. I check the gap again after tightening and spinning the engine, sometimes I find after that I need to adjust again. Take the glow plugs out to make it easy to turn engine.

On engines that don’t have hydraulic lifters, it’s important to adjust the valves, so I do mine more frequently than the manual says.

Looks like this repair is easy, just have get the old screw out, might need to take the rocker arm off to so that from the under side of the arm.


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[gssz]

Thanks for the additional info! Now that I learned the hard way what NOT to do, I should have the confidence to adjust the valves on my 2000 Tacoma (2.4L). On the small single cylinder motors I just got those nuts hand tight and they never moved, but I have two good torque wrenches and I thought it would be more "professional" to torque them to spec.

Should I adjust the valves toward the low end of the spec? In this case it would around .006".

 

[gssz]

Thanks for the additional info! Now that I learned the hard way what NOT to do, I should have the confidence to adjust the valves on my 2000 Tacoma (2.4L). On the small single cylinder motors I just got those nuts hand tight and they never moved, but I have two good torque wrenches and I thought it would be more "professional" to torque them to spec.

Should I adjust the valves toward the low end of the spec? In this case it would be around .006".

 

[North Idaho Wolfman]

Thanks for the additional info! Now that I learned the hard way what NOT to do, I should have the confidence to adjust the valves on my 2000 Tacoma (2.4L). On the small single cylinder motors I just got those nuts hand tight and they never moved, but I have two good torque wrenches and I thought it would be more "professional" to torque them to spec.

Should I adjust the valves toward the low end of the spec? In this case it would around .006".

No you're better off to adjust them to .008.

Also turning the motor over one 360* won't put all the valves in there proper placement to adjust them.

 

[gssz]

No you're better off to adjust them to .008.

Also turning the motor over one 360* won't put all the valves in there proper placement to adjust them.

Thanks - then I wonder what they mean by "overlap position" in the 2200 manual? Mine is a 2230 so it may be different - or more likely, I am clueless about what they mean

 

[D2Cat]

The overlap is the instant the intake and exhaust valves open and close at dead center.

 

[beex]

No you're better off to adjust them to .008.



Also turning the motor over one 360* won't put all the valves in there proper placement to adjust them.

I agree, don’t go on the low end of the gap range, different engine wear differentially, some engines the gap goes down with wear, some go up. I found on when I adjusted valves on the BX, the gaps where mostly to low. IMHO gaps going too low is worse than too high, a not full seated valve during combustion is a really bad thing.


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[gssz]

The overlap is the instant the intake and exhaust valves open and close at dead center.

So then I need to find the overlap position for pistons #2 and #3 individually?

 

[gssz]

I agree, don’t go on the low end of the gap range, different engine wear differentially, some engines the gap goes down with wear, some go up. I found on when I adjusted valves on the BX, the gaps where mostly to low. IMHO gaps going too low is worse than too high, a not full seated valve during combustion is a really bad thing.


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Thanks! in that case they might have been perfect to begin with, but now that I messed it up, I will readjust them to .008