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Alabama_Hokies
02-25-2007, 11:16 AM
Hi,

I am new to this forum and have searched the archive to make sure I am not asking a question that has already been asked. Surprisingly I did not find the topic.

I was doing some front end work on my TR6 and ran into a rather odd lubrication spec. Does anyone know about lubricating the lower trunnion on the front end of TR-6. The book indicates that the proper lubricant is 90 weight EP gear oil. In addition I found the same reference on Rimmer Brothers Web site which says not to use grease. This is rather strange and to make it stranger there is a grease fitting on the trunnion. Has anyone seen this on this, or something similar on another vehicle?

Thanks,

Dave

TR6oldtimer
02-25-2007, 11:35 AM
Yes this does seem to be a conundrum, but the 90W gear oil is the proper lubricant. You will notice the trunnion is a screw joint with a very snug fit. So as you rotate the vertical link in the trunnion the link will move ever so slightly up and down altering the geometry of the front suspension. Over time, the vertical motion will push grease out of the treads. This problem is resolved by the use of oil which is very much less viscus and will flow in the joint.

All this said, many Tr's are on the road that have not seen oil in the trunnion since the car left the factory.

My suggestion is to use grease if that is what has been used in the past, just more frequently then recommended. Use oil on new or rebuilt systems.

Ray

DougF
02-25-2007, 11:47 AM
Welcome to the forum. If using grease, buy a good quality high tack/high pound out product. Castrol makes a decent grease, as does Lucas. I don't recall which Castrol product is the best so you would have to ask the retailer. Lucas' red grease is good.

70herald
02-25-2007, 12:03 PM
Hi Dave
First of all welcome to the forum!

90w. gear oil is what you should be using for a bunch of reasons.
I get it in there by using my grease gun which is designed for bulk loading. I just fill it with oil, give it a few squirts to get out the grease and it is ready to go.
Since your trunions are probably filled with grease I would spray some WD-40 or PB blaster in a few times to soften up the old grease first. Then pump away. The old grease will eventually get dissolved into the oil.
Yisrael

MDCanaday
02-25-2007, 01:33 PM
I like the modern Moly/high temp greases. if you hit this zerk at the same time as all the others on the chassis you will never have a problem.
MD(mad dog)

MadMarx
02-25-2007, 02:09 PM
The discussion if grease or oil goes round the world and some say grease, some say oil.

For my part I use a moly grease.
Reason:
I suppose that it is easier for dirt to enter the trunnion when lubed with oil.

I put in grease once a year.
I never had a sign of wear and I do some track events and several thousands of miles highway use each year.
All in all I have run about 100000 mls with the current trunnion.

Basil
02-25-2007, 02:55 PM
Welcome to the forum! I would agree with Mark - I'd use grease as well for all the reasons he mentioned.

By the way, if you ask a question that's been addressed before we won't cut your head off. In fact, often times bringing up previous topics allows new members who may not have been involved in the original thread to chime in. Its not a bad idea to do a search to see if you can get an answser, but it's not a requirement either.

If there is one thing I hate is being on a forum where someone new posts a question and other's jump all over them because "that has already been discussed." Really not a good way to make people feel welcomed. Nope, we don't play those games here. If you can get your question answered in a search that's great, but otherwise, just ask your questions (and I own the place).

Cheers,
Basil

PS: Where are you in Alabama? I go to Huntsville often on business.

DNK
02-25-2007, 03:05 PM
Who the heck is basil. Must be a new guy/bcforum/images/%%GRAEMLIN_URL%%/devilgrin.gif

kodanja
02-25-2007, 03:09 PM
Lord, King, Emperor, DA' Man, The Big Cheese, The final Word!!!

Alabama_Hokies
02-25-2007, 03:11 PM
Thanks for all the input!!

I think I will go with the oil since I have already removed, cleaned and inspected the trunnion. And it looks good. That said I did not really notice when I took it apart if it was oil or grease, but I think it was oil. I will check closer when I do the other side.

Just to add to the discussion, if 90 is good, would 140 not be better, still flows but a bit more viscous might be good?

Basil, I am in Huntsville. When are you coming through again. First Tuesday of each month is the NABMS (North Alabama British Motoring Society) meeting.

Dave

MadMarx
02-25-2007, 03:16 PM
I think I will go with the oil since I have already removed, cleaned and inspected the trunnion. And it looks good. That said I did not really notice when I took it apart if it was oil or grease, but I think it was oil. I will check closer when I do the other side.

If you do so, make sure that the lower cover plate is soldered in place so that the oil remains inside and don't leave downstairs.

Cheers
Chris (big fan of John Cleese)

TR6oldtimer
02-25-2007, 03:19 PM
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Just to add to the discussion, if 90 is good, would 140 not be better, still flows but a bit more viscous might be good?
[/QUOTE]
If 140 is better then it would hold that grease is best.

No, stay with the specified viscosity. As the vertical link moves up and down it creates a pumping action that moves the oil around the threads.

Ray

MadMarx
02-25-2007, 03:23 PM
I throw this in....

A rule in mechanical engineering is that slow moving parts are lubed with grease, fast moving parts with oil because of the hydrodynamic pressure that occurs then.

John_Mc
03-10-2007, 03:48 PM
My local parts store only had valvoline 85w gear oil. Will that be okay, or should I keep looking? This is for reassembly of the new trunnion on the vertical link, not just routine lubing. Thanks.

PeterK
03-10-2007, 04:23 PM
I think you should look for outboard lower end Hypoid EPA 90W oil at your local boat yard.

John_Mc
03-10-2007, 09:49 PM
Thanks Peter. I'll check there.

And how do I know when the trunnion is on tight enough? I put it on today and thought I'd go until it could go no more, but I took it only as far as I could before the rubber cap looked too deformed.

71tr
03-10-2007, 10:01 PM
Snug it up then back off a turn or two so that everything operates smoothly and the rubber cap is not deformed.

PeterK
03-10-2007, 10:02 PM
"Screw the trunnion on to the vertical link as far as it will go, then unscrew it to its first working position" so that it lines up with the lower wishbones. "This will allow the trunnion to turn at least 60 degrees to either side of the straight ahead position without binding."

John_Mc
03-10-2007, 11:29 PM
I think I'm there. Thanks, guys!