TO-35 problems with new temperature gauge sending unit

This message is a reply to an archived post by dg7766 on March 11, 2019 at 13:41:54.
The original subject was "f40 temp gauge".

While replacing the panel gauges on my 1955 TO-35 I have encountered similar problems with not being able to use a new sending unit that is part of the new temp. gauge assembly. The threads in the
housing for the thermostat are 5/8-18. The OEM sending unit is 1" long and all of the after market sending units are 1 1/2" long. The longer
sending unit will bottom out on the bolt that holds the thermostat cover onto the thermostat housing and makes it impossible to use the gauge and
sending unit without a bushing to space the sending unit and retainer out from the housing. The bushings provided by all after market units and the
units available from Massey Ferguson dealers are too large or are too large and are pipe thread. What is needed is a bushing that has both internal
and external 5/8-18 threads. I am fortunate to have the skill sets to make the required bushing. I had a piece of 1" brass hex stock from which I
cut a piece 1 1/4" long. I drilled a hole through at 5/16" diameter for clearance for the new sending unit. Next I drilled a hole in one end
approximately .450" deep using a 9/16" drill bit and tapped the hole 5/8-18 tpi.. A 27/64" drill will work but threads are 55% to 65%. Next I
turned the part around and turned an O.D. to .625" X .450" and threaded it 5/8-18. If you do this and have a clearance problem with the hex
interfering with the thermostat housing , you have room to turn a shoulder on the male end behind the end of the threads and towards the center of
the bushing which could be anywhere from .750" to .900" diameter which should give you clearance to tighten the bushing into the housing. I hope
this helps.
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Thanks for the comment Steve. Your solution sounds good on the surface but the problem is that I searched every available temperature gauge that I could locate including the ones from the Massey Ferguson dealers and they all shared the same problem when it came to my tractor....they wouldn't work. I have visited with many dealers as well as Antique Tractors et al. and this was the only way I could make the unit work. To my knowledge all the sending units are 1 1/2" long and none have a bushing with the correct threads. If you know of any that will work please post the source so that others may avail themselves.
 
Thanks for the comment pomester. I could make some more in the shop but I did this on a manual lathe and CNC would be the most cost effective. I have
over an hour into this one. If there is a way to create an order list and if I could get enough interest to make it worthwhile I would probably do it.
I was mostly wanting to help others like myself with a solution that would allow them to utilize what is out there. I am curious as to how many
tractors share the same style of thermostat housing.
 
its been about ten years since i replaced a temp gauge on one of my 35's. I also ordered the wrong one too and after realizing that I eventually found the correct gauge and sending unit.

I will look in my "archives" and see if I can find where I ordered the correct unit from.
 

I found one but this site will not allow me to post the link.

send me an email and I will send you the link.
 
Brilliant work on the bushing.50 years ago I installed a new heat gauge on my TO20. I had same problem as you. What I remember is making a a spacer that slid over the too long bulb from copper tubing with a flare on one end. t did work as it is still in use today.
 
Received this from the parts dept. at our local MF dealer. It is a reply to his inquiry.

Yes, the probe end of the capillary tubes on most of the after-market temperature gauges are too long. Ferguson and MF had problems with this too.



Initially the problem was with the TE-20 and some TO-20 engines, Continental Z120 gas engines.

An adapter, MF part # 181780M1 and gasket, MF part #181530M1 were used to address

the problem. This adapter and the clips to hold the capillary tube were included when the gauge was sold as an accessory as MF part # 181748M91.

The adapter makes the hole for the probe or bulb 9/16" deeper.

Originally the bulb or probe on the temperature gauge was 1" or less.



* The one in the picture appears to be one of the early versions.



Even so, the 1" length was too long for the TE-20 with Z120 Continental engine so the adapater was needed.

In later years I used these adapters on after-market gauges with probes that were too long.



Then in the 1960's Stewart Warner, MF's supplier, made the probe or bulb longer, enough that the probe would not work on the TE/TO-20 and TO-30.



A special shim or washer, MF # 363989X1 was issued to solve the problem.

Stewart Warner then shortened the probe and the problem was solved.



The shim is only about 1/8" thick but this is enough to provide clearance for the 1 5/16" bulb. I doubt if the shim would solve the problem with the probe pictured as the probe appears to be over 1 1/2" long.



Today, many of the gauges coming from after-market suppliers, usually from overseas, have probes that are too long.



Steiner Tractor Parts shortened the length of the probe on their part # ABC1593 which solved the problem.



I have also used Stewart Warner Temperature Gauge #82210-48 which has a 48" long capillary tube without a problem on the TO-20, TO-30, TO-35 and MF-35 with Continental gas engines without a problem.



Stewart Warner also makes part # 82210-60 with a 60" long capillary tube which works better on the F-40, MF-50 and MF-65 tractors with Continental gas engines.

I have these Stewart Warner gauges and can check the length if you'd like.



In summray, the quickest solution might be getting either the Steiner #ABC1593 or the Stewart Warner 82210-48 gauge
 
Thanks for the info Steve. I also just received similar information from MF. For my tractor I think anything over 1 1/8" would interfere and be crushed unless I spaced it out. There is a reference in the note I posted to a shim that was provided to prevent this. My problem is solved with the adapter I made but you were right about the right part being available.
 
Yes, the probe end of the capillary tubes on most of the after-market temperature gauges are too long. Ferguson and MF had problems with this too.



Initially the problem was with the TE-20 and some TO-20 engines, Continental Z120 gas engines.

An adapter, MF part # 181780M1 and gasket, MF part #181530M1 were used to address

the problem. This adapter and the clips to hold the capillary tube were included when the gauge was sold as an accessory as MF part # 181748M91.

The adapter makes the hole for the probe or bulb 9/16" deeper.

Originally the bulb or probe on the temperature gauge was 1" or less.



* The one in the picture appears to be one of the early versions.



Even so, the 1" length was too long for the TE-20 with Z120 Continental engine so the adapater was needed.

In later years I used these adapters on after-market gauges with probes that were too long.



Then in the 1960's Stewart Warner, MF's supplier, made the probe or bulb longer, enough that the probe would not work on the TE/TO-20 and TO-30.



A special shim or washer, MF # 363989X1 was issued to solve the problem.

Stewart Warner then shortened the probe and the problem was solved.



The shim is only about 1/8" thick but this is enough to provide clearance for the 1 5/16" bulb. I doubt if the shim would solve the problem with the probe pictured as the probe appears to be over 1 1/2" long.



Today, many of the gauges coming from after-market suppliers, usually from overseas, have probes that are too long.



Steiner Tractor Parts shortened the length of the probe on their part # ABC1593 which solved the problem.



I have also used Stewart Warner Temperature Gauge #82210-48 which has a 48" long capillary tube without a problem on the TO-20, TO-30, TO-35 and MF-35 with Continental gas engines without a problem.



Stewart Warner also makes part # 82210-60 with a 60" long capillary tube which works better on the F-40, MF-50 and MF-65 tractors with Continental gas engines.

I have these Stewart Warner gauges and can check the length if you'd like.



In summray, the quickest solution might be getting either the Steiner #ABC1593 or the Stewart Warner 82210-48 gauge
 

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