TR4/4A Lower Trunnion question

[gubba]

Hi people. I'm trying to chase down a caster problem ( shaking on the passenger side at 60 MPH ) so I just replaced the upper ball joints ( they were shot) on my TR4A and as I was doing this I noticed a fair bit of play in the lower trunnions on both sides of the car. Is this normal? or should these be replaced to? TIA

 

[JerryVV]

Fair bit of play??? How much is that? I would say replace them but maybe the "play" is in the cross bolt sleeves and bushings and not the bronze trunnions themselves. Find out where the play is coming from and focus on fixing that issue. Where the top ball joints bad? never experienced the uppers going bad unless the car has not been taken care of with regular maintenance grease jobs.

 

[gubba]

The upper ball joints did not have any grease nipples and yes the were bad. Cheap ones I guess. I have replaced them with Lucas ones and they have grease nipples. The fair bit of play means that you can see it wiggle when you move the brake caliper side to side when it was unhooked from the ball joint. My question was is this normal or not! Not about maintenance. TIA

 

[Darrell_Walker]

No, it isn't normal for there to be play. If you are lucky, just new bushing and stuff will solve it, and the hole in the trunnion is still round.

Also, there is some debate on how much torque to use on the bolt. The TR4A factory manual was just an addendum to the TR4, but that joint is much more like the TR6 in design. I've chosen to use the TR6 setting, rather than setting a clearance like the TR4 calls for.

 

[trrdster2000]

gubba, Why not do the whole lower since you will be a couple bolts away from the "Full Monty". Vick Brit has the kit as does Moss and TRF, but you should be able to get by on the trunnion with just bushings and washers and if not then you can just order the brass trunnion as needed, (one or both).
Here's the page at VB: https://www.victoriabritish.com/icatalog/tc/full.aspx?Page=115

Wayne

 

[gubba]

Yes that is what I will do. I have ordered the whole trunnion replacement kit from British Parts North West. I will just replace both sides. Off to Tacoma on Friday for the ATDI so I need to get this done ASAP. Thanks for all your input everyone.

 

[KVH]

Shouldn't be any play in those trunnions, and like Darrell says use the TR6 torque setting; if you're traveling soon I'd "over order." It's fun to do. You explain it sheepishly sometimes, but at least you have extras. I ordered an extra trunnion and was glad I did since one I received was defective (that little plate on the bottom). You want that plastic, rubber, steel rebuild kit, too, and maybe replace the wheel bearings and control arm bushings at the same time. Been awhile so I'm recalling the full measure of all the fun. Those lower, inner control arm bushing are a terror at times, so maybe leave those alone if they're in good shape. I guess realign the toe in with a Moss gauge. Good luck.

 

[gubba]

Also, there is some debate on how much torque to use on the bolt. The TR4A factory manual was just an addendum to the TR4, but that joint is much more like the TR6 in design. I've chosen to use the TR6 setting, rather than setting a clearance like the TR4 calls for.

What would that torque setting be? Please.

 

[Darrell_Walker]

What would that torque setting be? Please.

Torque specs from the Bentley TR250 and TR6 manual:

Lower wishbone mounting bracket to frame 20-25 lb/ft
Lower wishbone to mounting bracket............38-46 lb/ft
Lower wishbone to vertical link.....................50-65 lb/ft​