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TR2/3/3A Speedometer Works Removal

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Joel M

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Does anyone know how to remove the works from the speedometer housing? I tried to follow Anthony Rhodes instructions from his repair manual, but the reset (which is functional) bottoms out before making it into the case. I am probably short about 1/8" to 3/16". I've tried finessing the assembly in every possible position, but cannot get the shaft clear. So what's the trick? They got it in there without damaging it, so there must be a way to get it out.

(from A. Rhodes repair manual)
"To remove the speedometer works, first remove the metal bezel and the glass. Remove the two screws on the back and, if necessary, the tiny screw holding the reset cable (TR2-4). Then press the reset shaft (TR2-4) into the case and then push the threaded end (where the speedometer cable attaches) inward. The works should slide forward out of the case. There may be some adhesion to the rubber gasket inside the case, If the works do not move freely check the reset shaft and be sure that it is not catching on the case. Use a screwdriver to press it free."

Joel
1959 TR3A TS57134L
 
Try turning the reset knob as you push it inward. Sometimes it catches on the reset gear rather than meshing with it. It may take several tries to get it lined up.
 
Joel, Getting the trip shaft in/out of the cast-type case always is a struggle. I also wonder how they did it at the factory. I have one where a PO ground the shaft down, stopping just short of the screw hole.

Its difficult to describe, but try rotating the gauge 'upward' as you push the shaft. The curve of the case may give you a bit more room. I remember it was difficult no matter what I did, and the upper shaft ended up slightly curved from all the pushing to get the lower end to pop inside the case. I'll look at one of my spare ones to see if I can figure out if there was a trick. I think I just kept muttering and fiddling...
 
I confirmed that it was not catching on the reset gear, so there was full engagement. Having said that, I continued to work with it and finally got it out. Unfortunately, there was a bend in the shaft. That was easy to straighten out, but I'm not sure how I'm going get it back in without re-bending it. I will go ahead and first attempt repair and cleaning (the gauge has been sitting around for over 30 years, and the worm gear will not turn). Please let me know if you figure out the if there is a trick. I did consider grinding off the end of the shaft, but I think I will use that as a last resort.

Joel
 
I disassembled both the speedometer and the tachometer. No issues with the tach, but the speedometer input shaft was seized and the trip odometer plastic gear has two broken teeth. So I guess I'm in the market for either a spare gear or an entire speedo I can break down for parts. If anybody has one they are willing to "part" with, please let me know.

Also, I would appreciate advice on grease for the input shaft. The repair manual indicates that a light grease should be used. Any recommendations?

Joel
 
Joel, Here is one on eBay, but NOS pricey. It has 32 teeth but is not really plastic; phenolic I think. I have a really nice TR4A speedo that also has a stripped odo gear - if I get a parts speedo I'll let you know. The problem is a used speedo may have the same problem.

https://www.ebay.com/itm/Speedomete...-Fits-Triumph-TR2-TR4-Jaguar-XKE/312989327700

P1110748.jpgP1110751.jpg

I took a picture of some wheels I have. The right one is a 32-tooth gear from a TR4A. The odo numbers were frozen from age and when I tried to test it, stripped a few teeth. (Note to self: Always fully dismantle first). I might try popping it off the shaft, reshaping the resin teeth, and replacing it in a different position so 'good' teeth can drive the pawl to advance the miles wheel.

The left is a 25-tooth wheel; not sure what it goes to (4.1 rear axle?) but the point is to count the teeth when replacing gears.

In the center is a 20-tooth plastic TR6 odo gear that cracked and stopped driving the miles wheel. I tried gluing it together but fitting the metal shaft opened the crack again.

Jeff
 
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There were 2 can used on the tr2 and 3. The early ones are pot metal are the more difficult to get the rod out, but it will go with fiddling ; the later ones are tin on the tr3 with 2 light bulbs and a high beam; the tr4 is tin with one light for the dial and one for high beam. I believe what happens is they sit and the grease gets hard and then the speedo gets put back to work and the frozen gears from the old grease holds the gears and the gear strips out. The early gears are hard to find and the later stuff is different. However, it is possible to put a tr4 into an early tr3 can with the curved front glass and no one would be the wiser.
Steve
 
Hi All,

Hope I am not too little, too late. I removed my speedo on Saturday and did some searching online. Came across this: Odometer Gears Ltd.
https://www.odometergears.com/
https://www.odometergears.com/products/Jaeger-Smiths/All/37

I spoke to Jeff this morning and ordered two 32 tooth gears, one to replace the odo drive and one to replace the trip-odo drive.

My saga has been four failed angle drives in 20 years due to speedometer binding. Had the speedo rebuilt twice. Apparently they used or installed NOS gears which (at this age) develop a hairline crack in them. Once the gear cracks, the teeth no longer nicely mesh with the worm gear - causing binding in the speedo head - which then results in a snapped angle drive.

These are newly manufactured gears (direct injection plastic) made from Celcon which includes graphite in the material and supposedly self lubricating. Not cheap ($25) but, better than $175 to rebuild the gauge with NOS parts which will only fail (again) and blow up my angle gear (again). Not to mention angle gears cost $45.

Hope this helps.

Bob
 
CJD said:
Why are you using the angle drive?
Click to expand...

John

I have a '66 TR4A with overdrive. It is designed to use a 66" speedo cable with angle drive which plugs into the OD unit. I've looked at disposing with the angle drive and running a 96" cable but, given where the OD is located, I didn't see how there would be sufficient clearance against the transmission tunnel. Why, do you have other ideas?

Bob
 
Sorry...didn’t realize this was an old thread. Got confused as I thought Joel decided to ditch the 90 drive. With a later car I get it. I have dealt with a few TR4 speedos and can say they seem to have scrimped a bit on manufacture on the later instruments. So, good decision to go with a better gear. If you still have trouble, you could even swap in the internals from an earlier gage to your face.
 
Joel M said:
I disassembled both the speedometer and the tachometer. No issues with the tach, but the speedometer input shaft was seized and the trip odometer plastic gear has two broken teeth. So I guess I'm in the market for either a spare gear or an entire speedo I can break down for parts. If anybody has one they are willing to "part" with, please let me know.

Also, I would appreciate advice on grease for the input shaft. The repair manual indicates that a light grease should be used. Any recommendations?

Joel
Click to expand...
Contact Powl Speedometer service in Lancaster Pa. 717-898-2552
 
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