Welcome to our resource for MG Car Information.
Triumph TR3 - Help with torque
|My neighbor is doing a body off restoration of a TR3. I wish I could tell you the year, but I'm not sure. I'm a diesel mechanic by trade, so he asked me for some welding and mechanical help. We need to know the headbolt torque and whether the fasteners are installed dry or lubed. Also looking for flywheel to crankshaft torques and whether loctite is recommended. Any help would be greatly appreciated.|
|All this is listed in the Original TR2 - TR3A Triumph workshop manual, or in the Haynes manual for TR2 to TR4 available from any TR parts supplier - Moss, Roadster Factory, Victoria British, etc.|
He should also get a copy of "How to Restore the TR3" from amazon.com or from Barnes & Noble.
The nuts for the head studs - 100 - 105 ft. lbs (with the engine cold) - no mention of oiled or dry. Re-torque them again after 500 miles.
Flywheel to crankshaft - 42 - 46 ft. lbs. I never used loctite.
Don Elliott, Original Owner, 1958 TR3A, Montreal, Canada
158,000 miles from new (over 78,000 miles since 1990).
|Don - What procedure do you use to re-torque the nuts for the head studs?|
|If the head is off, I run a die on the threads at the top of the studs so the nuts go on properly. Usually these threads stretch and become distorted. If you are worried, change the studs for new ones of the approved heat treat strength rating. Then, after re-mounting the head, I torque the nuts as per the zig-zag sequence in the book. After 500 miles, remove the valve cover and then the pedestal bolts for the rocker shaft. I back off the first nut as per the sequence using the torque wrench and when it's a bit loose or more, I re-torque the nut to 105 ft. lbs. Then I move to the next nut in sequence.|
The problem arises when you get to the rear corner nut where the brass faucet for the heater blocks access to that corner nut. Here you have 3 options.
1. Forget this one and hope it was and still is OK.
2. Drain all the water out the block (and maybe the rad as well), remove this heater faucet, torque the nut and reverse all the above.
3. Buy a "claw-foot" type of open end (or a full set) that fits the 1/2" square end on your torque wrench and reach under the faucet to loosen and re-torque that corner nut. You may have to grind the claw foot end thinner to slide under the faucet.
Then replace the rocker pedestals, valve cover, etc.
Don Elliott, 1958 TR3A
|Don, thanks for the detailed response. I'll suggest both books to my neighbor. In the meantime, I'll make sure to give him the URL for this board. It's a great resource that he'll want to take advantage of.|
|Allen - Tell him to click on the member page to sign up. It is free and secure. Never had a problem. He will then be able to check out the archives. Only members can check there. It's probable that his questions have already been asked and answered.|
If he is not yet a club member tell him to join VTR and the New England Tr Club. Where are you located ?
Don Elliott, 1958 TR3A
To see all my restoration pics, click on The Montreal TR Club
Then click on Member Cars as well as on Member Profiles. Scroll down to my name and enjoy.
This thread was discussed between 31/01/2004 and 01/02/2004
Triumph TR3 index