Another Trunnion Question

[Bordfunker]

I bought my Herald from a dealer who specialises in Rovers & MGs, and prior to the sale they serviced it, including greasing the trunnions!

 

Having just acquired a Wanner grease gun, I have pumped the trunnions full of EP90, forcing the grease out from around the seals.

 

Is this good enough, or do I need to strip the trunnions down, clean them out and then re-install?

 

The steering is considerably lighter post application of said EP90, which hopefully indicates that all is well, but still worried having read numerous Trunnion failure horror stories.

 

Karl

[dougbgt6]

In  the hypothetical situation where I had paid someone to service my car and then discovered they had greased the trunions, I would be happy (well not happy, exactly) to pump it out with EP90.

 

However, your car is new, to you and you don't know what's happened to it in the past. In that situation I would strip the trunions down and inspect them and the vertical link threads. Your looking for small cracks or damage particularly at the top of the vertical link thread. It's an easy enough job that won't take more than a couple of hours.

 

We oil the trunions because in olden times grease was water based and dried out, turning to nasty abrasive white powder. Grease is no longer water based and shouldn't do any damage.  We still use oil because trunion material likes oil better than grease. They are bronze, I think, I got jumped on by JohnD on one occasion for saying brass, not a pleasant experience!   

[Bordfunker]

Many thanks for the response.

 

Do I need a spring compressor to remove the trunnions, or it simply a case of slackening off the lower wishbone/shock mounting bolt, and then removing the bot attaching the Trunnion to the wishbone?

 

Karl

[Mike R]

For my sins when I purchased my GT6 in 2000 I greased the trunnions not realising the triumph laws. Soon after I read about the need for EP90 and potential for broken suspension, so did exactly what you did and back filled with EP90.

Roll on 10 years and I had an MOT advisory on both trunnions for excessive play. I consequently replaced both uprights and both trunnions with wear apparent on both upright threads.

So, was the wear because of that initial greasing? I don't know. But the idea of a potential suspension fail at speed scares me!

 

As Cilla used to say - the decision is yours.

What you can do though is at least once a year check for play in the trunnion by jacking up the front, and leavering each tyre up and down and watching the trunnion. When I had my worn trunnions you could see the trunnion move slightly relative to the upright demonstrating wear in the threads.

Mike

[dougbgt6]

Karl, no spring compressor required,  you have the procedure correct. 

 

Mike, I had a vertical link break shortly after I bought my car, it was 5 years old! I suspect the trunions hadn't been lubricated since they left the factory. I replaced both links and trunions but, 38 years later, I got an MOT fail for slack trunions. Would you Adam and Eve it! 

 

The VLs checked out visually OK so I replaced the trunions, expecting to replace the VLs if there was still slack. But, no more slack. My MOT man, who was once a Triumph apprentice, says it's the trunions that wear and the VLs only wear when they're not lubricated.

 

Yours trunions only did 10 years but how many miles?  In 38 years my car only did 35k miles. I guess it's mileage and regular lubrication that's important. Nothing lasts for ever!

 

Although I have heard of failure in a straight line at speed, it generally happens on full lock when the VL is under most strain. That's how mine went, even so it was a most exciting experience!

[Mike R]

I do about 2000 miles per year, but then I don't know how many miles were on them before I bought the car. So yes could have been just age & miles.

[Bordfunker]

I think I'll play it safe and remove the trunnions, clean, inspect, and then dependent on condition, either just fit new seals & bushes, or replace the trunnions as well.

 

It makes sense that the VLs would wear less than the trunnions, given that the former are steel, and the latter much softer bronze.

 

Thanks for the feedback and sharing of experience, much appreciated.

 

Karl

[dougbgt6]

Good plan Karl, sounds like the right move.

[Pete Lewis]

Just to add the trunion lube is an oil bath the cavity acts as a resevoir to bold the oil

with movement the oil is keeping the parts lubricated , if you use grease it gets squidged out the threads

and early wear starts,

 

And without a metalurgical memory the hard part often takes the wear leaving the soft untouched

 

if unsure a look see is a wise move, you may need to remove the hub /disc to rotate the trunion.

 

pete

[Guest]

Karl.

 

Trunnions is a key topic, so if you could take some photos and post that will be useful and interesting to have a look at them for wear etc.

 

If you can.

 

Regards.

 

Richard.

[Pete Lewis]

and apart from wear and tear if there is any corrosion indentations these induce a start of the crack that generally shears off when turning onto the drive ,, some have had higher speed mishaps , but the last straw does tend to happen when under more slow heavy cornering loads ,  moggies and others also suffer this surprise  let downs .

 

its not just triumph

[Bordfunker]

The trunnion inspection will probably have to wait until next month, but I will try and take some photos of the whole procedure.

 

The engine mounts will probably done at the same time as they are both shot.

 

Karl

[daverclasper]

Hi Karl

 

Don't know how bad yours are, though, having read a few threads on current repro engine mounts, they appear to be terrible (lasting a few months).

 

Mine ,which were on car when I bought it over 3 years ago have always looked pretty shot, but haven't given trouble yet.

 

Might be worth bearing in mind, though there may ok new ones out there?.

 

Dave

[Bordfunker]

The one on the driver's side is totally shot, and the passenger side not far behind.

 

They are so bad that the gearbox rubs on the inside of the gearbox tunnel if you rev the engine!

 

Karl

[Pete Lewis]

Its sounds a good idea to check the cotton reels at the gearbox end as well

 

pete

[Bordfunker]

The cotton reel mounts on the gearbox look to be brand new. I did a gearbox oil change at the weekend, hence discovering the chafing on the gearbox tunnel cover.

 

I think the are the only thing keeping the engine in place.

 

Probably explains the vibration when I try and exceed 55!

 

Karl

[Stuart R]

Can I ask another Trunnion question, please?

 

This weekend, I had to replace the upper balljoint on my Herald's front suspension.  The gaiter on the ball joint had split and turned to a gloopy mess.

 

With nothing holding the vertical link at the top, I was aware of quite a bit of play in the trunnion when trying to re-assemble the top joint.  This was not apparent when the suspension was reassembled, nor at the MoT last week.

 

Is this just due to the coarse thread used, or does it sound like I need to strip it down and inspect?

 

Not that impressed with the modern replacement ball joint I fitted and hear similar stories about new trunnions.

 

Thanks!

 

Stuart.

[Pete Lewis]

Was the wobble from the thread clearance or the trunnion bushes or loose through bolts

 

there is a designed clearance as it must have to be able to rotate

 

I would not expect obvious slack , you are a extended distance away from the trunion

Which magnifies clearances

it doesnt sound too good, a good look look see might be advisable

pete

[dougbgt6]

Your MOT man may not be as trunnion aware as mine (he was an apprentice in a Triumph dealership, unlucky for me   ) He put a long bar under the suspension and jacked it up and down, the play in the trunnion was obvious. Maybe your bloke didn't do that?  

 

Yes, wise to have it apart. The thing to inspect closely is the top of the thread on the vertical link, this is the point where it will break, any deterioration here and a new vertical link is required.

 

If it's OK, just new trunnions, Replacements seem OK but some leak through the metal insert in the bottom. People solder or glue/seal the inside bottom of the new trunnions.

[Stuart R]

Thanks Pete & Doug, the whole assembly tilted towards me at one point, so I know there was freedom in the trunnion through-bolt, but once the vertical link was upright, I could still feel this play, so that would point towards thread-clearance.  In other words - worn?

 

Had a look again tonight, with the front end jacked up - can't see any movement when levering-up under the road wheel with a stout plank of wood.

 

Probably think it's spanners out again on my next day off. 

[Pete Lewis]

Stuart,  with a full strip down ( Grrr)  with the trunnion off and clamped in a vice you should be able to replicate the slack on the upright and see clearly where its coming from

 

the trunnion  should be a nice fit not slack     let me know if you want help

 

Pete

[dave.vitesse]

Also check the Trunnion holes in the lower wishbones are not worn oval/elongated.

 

Dave  

[Stuart R]

Hello Pete & Dave,

 

I will try to take a closer look when time allows, the play definitely seemed to be between the Trunnion & Vertical link.

 

I'm going to gather a few new fixing bolts together first as the ball joint's nuts and bolts were hard work to separate - don't want anything snapping.

 

Thanks for your kind offer Pete, will keep you posted.

 

Stuart.

[Fasterandfuriouser]

I bought my Herald from a dealer who specialises in Rovers & MGs, and prior to the sale they serviced it, including greasing the trunnions!

Having just acquired a Wanner grease gun, I have pumped the trunnions full of EP90, forcing the grease out from around the seals.

Is this good enough, or do I need to strip the trunnions down, clean them out and then re-install?

The steering is considerably lighter post application of said EP90, which hopefully indicates that all is well, but still worried having read numerous Trunnion failure horror stories.

Karl

Trunnions don't fail because of grease, they fail from damage, old age, corrosion and wear.

They used to break back in the days when I used to buy Triumphs from a Triumph dealer.

It's not helped by the fact we now use wider sticky tyres compared to the non gripping crossplys of yore.

[dougbgt6]

Grease in olden times was water based and used to deteriorate, if left alone, to a dry white gritty powder. I found some of this in my trunnion when my vertical link broke (1978). The previous owner hadn't lubricated the trunnions in 5 years!

 

Triumph originally said grease for trunions, but during the manufacture of the TR4 (I think?) they switched to oil. Grease is no longer water based and doesn't turn to damaging grit, but we still use oil because it's the better lubricant for the trunnion.