RK37HC A/C belt adjustment

[DonRybak]

Yesterday when I turned on the A/C the belt randomly slipped causing a squeal. I checked the tension on both the fan belt that runs the alternator and the one that runs the A/C compressor. Both had quite a bit of play so I tightened the one running the alternator but the one for the A/C compressor has me stumped. There's a pulley mid way in the length of the longest run of the belt that appears to be used for tightening the belt. There's a bolt on the pulley assembly that looks like if turned will tighten or loosen the belt tension but I can't figure out how to access it because it's right behind the exhaust pipe. I dropped the exhaust pipe but the outlet from the DPF that the exhaust pipe slides over is in the way. There's not enough clearance between the bolt and DPF for a ratch and socket. The outlet from the DPF puts too much of an angle on an extension for the socket to bite the bolt head. I can get an open end wrench on it but can't get enough torque on it to turn. Has anyone with a RK37 cab model changed or adjusted the A/C belt or anyone have ideas??? Thanks.....Don

 

[g8erh8er]

I have the RK55. If you check my past threads you should find one where I experienced the same issue as you. If the 37 is setup similar to the 55, you may only be able to actuate that nut with a crowfoot wrench adapter and long extension. That’s the only thing that worked for me. I included pics in the thread that may help.

Edit: Here's the thread RK55HC Air Conditioner Belt Tension and Mystery Fill Cap

 

[5030]

If it's like my Kubota's the idler pulley is only there to keep the belt on the sheaves.

 

[DonRybak]

Thanks for the replies. g8erh8er, I did a search on a/c belt adjustment but didn't see your post. I went to Rural King today and talked with the lead tractor rep and he showed me how to adjust the belt tension. The setup is similar but different than you RK55. There is a bolt in the middle of the tension pulley that appears to hold the pulley assembly to the bracket. But it also locks the pulley assembly in place. He said I need to loosen that bolt first then the other bolt that tightens the tension can be turned fairly easy with a box end wrench. I'll remove the exhaust pipe again for more room to turn the wrench but I hope to get a chance to work with it tomorrow. Sure wish the adjusting bolt was as accessible on the RK37 as it appears to be on yours. I'll post the results once I do it for reference for other RK37 cab owners......Don

 

[sengli]

While mine was in for some other issue, they noted my belt was loose too. Rather than mechanically tightening the belt, they sprayed belt dressing all over the front of the engine. Took me hours to clean it all off. Sticky nasty black goo. Then I tightened the belt via the mechanical routine.

 

[DonRybak]

It's been so freaking hot, low 90's and super high humidity, and at my age I haven't wanted to risk being out there for too long and getting heat stroke. Late this afternoon I did see what the Rural King rep said about the bolt on the front of the idler pulley. Not enough room between the pulley and fan to get a socket on it. He said they used a box end wrench then slipped a piece of pipe over the end of the wrench to get enough torque to break the bolt free. I did get a 14mm wrench on the bolt but couldn't break it loose. As soon as I feel comfortable being outside for a couple hours straight I'll pull the exhaust pipe for extra room and give it a shot with the pipe trick. Sengli, was it your a/c belt or the alternator belt? My alternator belt was loose too but that was an easy adjustment but the a/c belt not so much.

 

[DonRybak]

Well, today I d getting that pulley bolt loecided to give it a shot at getting the temsioner pulley bolt loose. The pipe trick worked but I felt that the ratching box end wrench was going to round off the corners of the bolt. I finally managed to break ot loose with a 6 point socket and a piece of pipe for leverage. Happy happy happy........ Then when trying to turn the bolt that adjusts the tension pulley it doesn't budge. Open room in this area is almost non-existant. Looking down from the top I see that the adjusting bolt goes through the bracket holding the tension pulley and attaches to the back of the pulley. Turning this bolt adjusts the pulley in or out depending on which way the bolt it turned. The kicker is that the bolt has another nut on it right inside the brackeyt that I assume is more or less a jam nut to keep the bolt from moving. Only thought I can com up with is a crowsfoot wrench.

 

[g8erh8er]

Be prepared to do some torquing on that jam nut. Mine was on there with a crazy amount of force.

 

[DonRybak]

Thanks g8erh8er........... Going to stop by Home Depot and Lowes to see if they have a set. My concern is that there's not enough room to get a straight shot on the nut even with a long extension. The DPF sits right in front of that adjusting bolt. Grrrrrr....... The DPF is in 3 sections and it I could take the end section with the exhaust exit pipe off that would really give a lot more room but not sure if that's the route to go. Questions as to if the metal gasket is reusable or not or even if there's something inside that section that might fall out keeps popping up in my mind. While I'm out today I might drive down to Rural King and see if the rep that told me how to break the pulley nut loose is working today. He's always been very helpful. Thanks again......

 

[agjones]

Be prepared to do some torquing on that jam nut. Mine was on there with a crazy amount of force.

It might be more than torque. Given the likelihood of vibration and heat there may be thread lock on the bolt. Heat it.