View Full Version : TR6 Rusted Trunnion Pivot Bolt

06-05-2018, 01:53 PM
After sitting for most of the last 15 years, and a chance meeting with a guardrail, of necessity I'm rebuilding the front end. I've beaten, wrenched, soaked, and heated most parts loose. And although I don't have everything loose yet, I'm currently working on the pivot bolt going thru the trunnion. The lock nut came off fine, but the pivot bolt seems to be rusted solid in the trunnion. The vertical link is off, its getting penetrating oil constantly, and I've put a 2 foot breaker bar with a 6 pt impact socket, and the bar just flexes. I haven't put the propane torch on it yet because of the nylon bushings. If (when?) those melt, is it going to make it harder to get off and clean up later ? I could put my daughters 260 lb boyfriend on the breaker bar, but I don't really want the bolt to snap, or the breaker bar. Any other methods or suggestions ?

06-05-2018, 02:02 PM
Have you tried putting the nut back on and hitting it with a BFH? It should just slide out from hitting it.

06-05-2018, 02:10 PM
Yes. First with a regular ball peen, then an 8 lb sledge. But it's not like I can get a really good swing at it.

Alfred E. Neuman
06-05-2018, 02:49 PM
Can you dismantle the suspension the rest of the way so you can take the trunion and lower wishbone that's held in by the bolt over to a press or vice. That way you can either press it out or get a good solid hit on it with a firm backing. Hitting it with it in the car is letting most of your hitting force get soaked up by the wishbone deflecting.

06-05-2018, 02:56 PM
Thanks. I like that idea. Although I'm still working on getting the last fulcrum bracket off the other side. I can't seem to get a wrench on that thin headed bolt. I'll see if this side comes off any easier. And I ended up cutting the top of the shock (OK,....damper) on the other side to get it off.

06-05-2018, 04:06 PM
Have you tried an impact wrench? Clockwise a few, counterclockwise a few, several repetitions.

Bob Hustead

06-05-2018, 04:32 PM
I just tried that. No luck.
Also had tried going both ways with the breaker bar.

06-05-2018, 04:40 PM
Could the bolt be bent as a result of the accident?

06-05-2018, 04:46 PM
This is on the other side.

06-05-2018, 08:15 PM
There's a bit of a dissimilar metal situation with the bolt and the trunnion and you probably have some galvanic corrosion going there that has frozen the bolt in place. If you can't get it out using a press and lots of Aerokroil, PB Blaster, etc, then it is time to put the torch to it and give it a few heat cycles to let the differential thermal expansion of the trunnion and bolt start breaking up the corrosion.

06-05-2018, 09:08 PM
I was wondering about that: whether brass would even rust, or if a steel spacer had got jammed in somewhere. With the vertical link off, with a wrench on the bolt head, only the trunnion moves with the bolt. (that I can see anyway) Is propane going to get it hot enough, and what becomes of the nylon? Does it melt out, burn, or become a gooey mess? BTW, I've been using Liquid Wrench to penetrate.

06-06-2018, 10:58 AM
It's been a while since I've gone into the front suspension on one of these, so a look at the parts catalog made for a quick refresher course in light of your question on the nylon bushings. First, it looks like I was wrong with the bit "dissimilar metal situation with the bolt and the trunnion." There is a steel sleeve that fits into the trunnion and then the bolt goes through that sleeve. That means there is still the potential for galvanic corrosion between that sleeve and the trunnion plus it also opens up the potential that the bolt is seized to the sleeve.

I wouldn't worry too much about toasting the nylon bits or the rubber rings that serve as seals since they should be replaced in any front end rebuild. The torch should still work to start breaking up the corrosion products in that you have three different coefficients of thermal expansion that you are dealing with. One is the brass of the trunnion, one is with the steel components and then the corrosion products. The corrosion products, being oxides, will have a lower CTE than the metals so the heat cycling will break up those bonds. It will likely take a few cycles of heating then letting cool back to ambient before repeating the process.

If it makes you feel any better, once I had to grab the "hot wrench" when trying to remove the jet needle from a CD-175 piston. Those suspension components are much more robust then the metal in the carbs so the odds of you hurting anything are rather low.

06-08-2018, 03:39 AM
More than likely the sleeve is rusted in there your never going to get it out with any kind of pb blaster your only chance is with a torch and that might not work you might just consider getting a new link

06-25-2018, 02:37 PM
After a short hiatus working on the "other" car, I'm back to the TR. After multiple heatings and then soaking with PB, the bolt is at least turning inside the trunnion, but not coming out. I have the spring plate compressed, and got the retaining nuts off. My Bentley manual says to remove the trunnion before removing spring, plate, and lower wishbones; which obviously is not happening. Before I lower the jack, is this going to work also ? Can I get the spring out with the trunnion still attached to the wishbones ? (I have one spring compressor bolt snugged down to hopefully take some of the tension off.)

06-25-2018, 03:27 PM
Yes, the spring can be removed with the trunnion in place. You will need to remove the damper, then run a something like the TRF spring compressor (RFT103) up there, remove the spring pan fasteners and then release the compression on the spring. Moss has a similar tool (386-895) or if you're in that "there's no hiding real money" mode, they offer a replica of the Churchill factory tool under their part number 675-075 at a much higher price.

Then you can remove the ball joint and the lower arms and get the sub assembly onto a press if you like.

06-25-2018, 04:14 PM
Thanks. The damper is already out. along with the ball joint and vertical link. I have a lot of respect for compressed springs (luckily not by experience), and just wanted to be safe.

07-06-2018, 07:49 PM
A quick update: Removed the whole lower wishbone as a unit. I finally got it apart last week, with repeated heating with propane torch over several days, and drenching with PB Blaster. Not sure what actually worked, but I got the job done. Also, to get a firmer hit with the hammer, I placed the "head" end of the bolt in a socket, and placed that on a 4x4 (No, not the neighbors Ford. A wooden one ) and that gave me a firm surface to pound against. Still took some good hits with an 8 lb sledge. Luckily, the trunnion on that side looks good. Nice round hole and not corroded. The problem was all in the steel sleeves being rusted to the bolt.
I still have one wishbone that hasn't come out of the fulcrum bracket yet. I'll have to try the torch on that when the days are a little cooler. It's 87* in the garage right now.

Also **** Can anyone suggest a website that accurately shows the sequence of the bushings around the trunnion ? I thought I had the old pieces in the right sequence, but it just doesn't look right. Primarily concerned about the water shield.

07-06-2018, 09:50 PM
Does this help?



07-06-2018, 09:53 PM
Yep ! That confirms it. I had prematurely stuck the nylon inserts in before sticking on the water shield. THANKS !!