John Deere H head torque sequence

[Otis]

I am ready to attach the head to the block on my 1943 John Deere H and want some advice on how to torque the head bolts. The spec is for 69 ft-lbs on six of them and 180 ft-lbs on the 3/4 in nut on the "bolt" which contains the oil
line. The manual says to torque the nuts evenly in small increments---how do you do this with such a difference in torque values?
Thanks for any help. Otis

 

[J.Wondergem]

Just bring them down on a percentage.

 

[jd man wis]

I would start with the center one and work around the inside nuts doing them all at around 20 foot pounds and go up 20 more on the torque tell you are up to close then 69 at end. I have never did the center one with the oil line at that high. If the rest are at 69 foot pounds then I also did the center at that. I have done 4 Hs and had no problems.

 

[Otis]

Thanks for your advice--your experience seems to indicate that the torque on the oil line is not that important, but there must be a reason the spec calls for 180 ft-lbs.
Otis

 

[Otis]

Great advice!!
Otis

 

[jd man wis]

I'm thinking that with the oil going thew there they want a good seal but iv use some engine sealed on it to the head then you have the lead washer under the nut and it works good. Iv never had any problems at 69 foot pounds. Iv seen some blocks have a crack in them by the center stud and I'm thinking at 180 is to much for it and that John deeres stud is to stretch some in the torque.

 

[Otis]

Thanks again---I will not go to 180 ft-lbs. Otis

 

[dan_41jdh]

The reason for the 180 FT-LB torque is because that's what Deere specifications call for. The illustration below is from Field Service Bulletin 147-S (May 15, 1944). It is the first publication by Deere that identifies torque values. The six smaller head studs on the "H" are 9/16" diameter so the specified torque is 1150 IN-LB which translates to 96 FT-LB, not 69 FT-LB. The single 3/4" stud has a specified torque of 2150 IN-LB which translates to 179 FT-LB (180 is certainly close enough). Those torque values are also seen in the aftermarket I&T manuals. And if one looks at the head stud pattern, you will notice four studs on the top row and only three on the bottom - this means the center stud on the bottom is effectively having to do the same job as the center two on the top row. Thus, there is a common-sense reason for a higher torque (and thus a greater clamping force) required of that single 3/4" stud.

 

[Otis Wolkins]

Thanks for the information from Dan--I have changed my mind and will go to 180 ft-lb