UB Head Bolts

Steve

Gentlemen,
This is a reminder that some time ago, a bulletin was sent to all dealers on head-torquing. This is a must in order to keep the gaskets from blowing out and also to keep the engine compression from entering the cooling system causing water to be forced out via the radiator cap.

Torque reading of 175 lbs. evenly torqued and in sequence is recommended on tractors listed below:

Gasoline: U, M5
LP: UB, Gvi
Natural Gas: 5 Star, G704, G705, G706

Power Units:
283, 425, 605, 403, 800

On diesel torque reading in 175 lbs. on the 5/8 stud bolts and 135 lbs. in the 9/16 stud bolts again torques evenly and in sequence.

UB Diesel, 5 Star Diesel, M5 Diesel, Gvi Diesel, 705 Diesel, 706 Diesel, 704 Diesel, 283 Diesel, 425 Diesel.

Torque reading on the following tractors is 100 lbs. torqued evenly and in sequence.

335, 445, 4 Star, Jet Star, 206 Power unit, 220 Power unit.

I recently installed the heads on a UTE and torques them to 150 lbs. That's as far as my wrench would read. As far as torquing the bolts under the water manifold, Snap-On sells a 15/16 head bolt adaptor for a torque wrench.

There is no reason for the studs to be sealed. Reading out of my I&T manual, they say to tighten water and intake/exhaust manifolds before tightening the head and blocks down. Then they say tighten head nuts from center outward and to a torque of 125-130 ft lbs on camshaft side(left side) and 105-110 ft lbs on exhaust manifold side(right side). 160 does seem very high. Have fun getting them there if you try. :)

The book doesn't say anything about using a sealer, but we used the Permatex High Temp Copper RTV on the UB. That Permatex Copper will seal anything, unless you have a cracked block. (We kept on changing out heads and head gaskets on the UTS, due to water in the cylinders, until we finally realized that the block was cracked up near the ridge on both cylinders of one block. The manifold mounts, where it mounts against the head, weren't level so it was putting a lot of stress on the block. We were starting to give up on the Permatex High Temp Copper, until we realized the block was cracked.) It is good stuff! I would stick with the high temp if you do use anything, because of the combustion temperatures that are stressed around the sealing rings on the gaskets.

One more note. Before you try to put the heads back on, the studs are kind of nice to have threaded in the crankcase for alignment reasons. But make sure they are cleaned, wire brushed, and shined up before you try to put the heads on. I'm sure you realized this when you took the heads off. Sometimes the studs can get caked on with dirt and grease so it is hard to remove and install the heads.

Best of luck to you and feel free to ask any more questions if needed.

Regards,

Trever

Steve

Trever