1972 Triumph TR6 looking for a purpose

I was looking at where the oil is collecting and trying to extrapolate back to the source.  It appears to be running around the back flange of the oil pan from the middle, but that still doesn't narrow down the source.  It could be the pan or the rear crank seal.  Putting sealant around this area wouldn't help, so something has to come out.  I may flip a coin to decide gearbox or oil pan.

We are having a warm spell (60 F), so the car came down off jack stands for tuning.  It's running really well and the tuning changes are getting smaller.  11 more miles yesterday.

Looking under the car after Sunday's drive, there is a *line* of oil on the ground, not just several drips.  So this problem needs to be addressed.  My contemplation has led me to wanting to pull out the gearbox.  This will let me see all of the potential leak areas and hopefully avoid removing the engine.  If I unbolt the oil pan and it can't be removed, I may be able to lift the engine just enough to get it out, but maybe not.  I've done the gearbox in 6 hours and the bonnet won't need to come off.  While I'm in there, I may need to replace an overdrive switch.  The overdrive was intermittent on the last test drive, but this could also be the oil level.

Another issue cropped up today during a longer tuning run.  There is a metalic sound coming from the back of the engine that goes away when the clutch is depressed.  It sounds like a bearing noise, so maybe the throw out bearing (11 miles is a little soon for it to bite the dust, though).  So there's the clincher for pulling the gearbox.

On the plus side, I was able to collect enough data to better tune the MegaSquirt ITB mode.  The curve of TPS at 90% load was slightly low for lower RPMs, and the fuel map needed retuning after correcting that.  I also took it up some steeper grades to tune the upper part of the map.  It's running even better now.  The injector dead time was also tweaked.

At least now I feel pretty good about where I'm at after the oil leaks are fixed.

In reply to JoeTR6 :

Noise that stops upon depressing the clutch is usually from the gearbox input bearing,or the layshaft bearings

TurnerX19 said:

In reply to JoeTR6 :

Noise that stops upon depressing the clutch is usually from the gearbox input bearing,or the layshaft bearings

I'm worried you may be right.  At first I thought the noise was the exhaust rattling on something, but there's no contact.  Then I noticed it went away with the clutch in.  The sound is more of a metallic rattle/scraping than a screech.  I'll try to get a recording before pulling it apart.

All of the gearbox bearings are new from TRF, FWIW.

Now that you have run it and worked the overdrive, is the oil level too low?????

TurnerX19 said:

Now that you have run it and worked the overdrive, is the oil level too low?????

That's also on my list of things to check.  I'll probably drain the oil before removing the gearbox and see whether any bad stuff comes out.  It has a magnetic drain plug, so should be obvious if a bearing is failing.  The overdrive was working great yesterday, so probably a bad interruptor switch or loose connector.  Even the new switches are flaky.

Here's a video looking at the clutch slave cylinder push rod.  I can make the noise go away by both pushing and pulling on the clutch lever.  Pushing on the lever is just releasing pressure from the throwout bearing and shouldn't affect the gearbox or crankshaft directly.  It sounds like the throwout bearing face is wearing on the pressure plate fingers.

Clutch Noise

No doubt that is the throwout bearing 'gliding or grinding' on the clutch fingers. I've done way too many clutches to count in TR6's now. If/when you pull the box, I bet you'll see wear on the fingers from the little running you've had. 

Couple things that greatly reduce this are using the alignment dowels on clutch and the alignment dowels on the trans itself when mating to the engine plate. Without those, the bearing does not run concentric to the clutch and it 'skids' on the clutch making noise and wearing down quickly. 

I used the alignment dowels on both the clutch and gearbox mounting.  The clutch is basically a TRF magic clutch kit; a Sachs Saab 900 pressure plate and a Gunst-style throwout bearing, but with an AP Racing friction disk.  Also a new bronze bearing carrier.  I guess we'll see, but I do expect to see a wear ring on the clutch fingers.  Maybe I forgot to put any grease on the fingers.

Hmmm... I don't ever grease the fingers. 

One other thought. For the last 20 years or so, I've used a return spring on mine. Various clutches through the years, but currently the same as yours excepting the bearing carrier. Spring pulls the bearing away from the clutch. Mounted between the slave ear and the pushrod end. 

oppositelocksmith said:

Hmmm... I don't ever grease the fingers. 

One other thought. For the last 20 years or so, I've used a return spring on mine. Various clutches through the years, but currently the same as yours excepting the bearing carrier. Spring pulls the bearing away from the clutch. Mounted between the slave ear and the pushrod end. 

I have gone dry and also put just a very light coating of high-temp brake grease on the throwout bearing face.  But yes, grease doesn't seem like a long-term solution to this issue.  I may also consider a spring to pull the throwout bearing away from the clutch.  I've also seen a release bearing kit (Gunst) that included a spring to keep the throwout bearing in full contact with the pressure plate.  I suppose the idea here is to keep the bearing from dragging on the fingers and let the bearing turn.

BTW, this is basically the clutch I have.  BPNW Clutch Kit

It's still too cold in the garage to start tearing into gearbox removal.  Also, we are currently temporarily hosting an adult child with a diagnosed mental condition.  Much of my spare time is spent keeping an eye on that situation.

In reply to JoeTR6 :

Good luck with getting your kiddo straightened out and back well again.

Sending you good thoughts.

It was near 60 F today, so I pulled the car out for more tuning and to freshen the oil leaks.  The car ran great, but the alignment needs some work.  It feels a little toed-out in the front but tracks straight.  Power off the line is really smooth and the clutch feels great.

Too bad it's still leaking oil like crazy.  The lower engine adapter plate is completely covered in oil.  So after the drive, the car went up on jack stands and I began pulling it apart.  The gearbox is almost out with just a few bolts left at the top.

Bummer. Assuming this could be in my future at some point, how are you planning to get the trans out without clanging around the interior too much?

AxeHealey said:

Bummer. Assuming this could be in my future at some point, how are you planning to get the trans out without clanging around the interior too much?

I had to pull the gearbox on the other restoration, and doing so did leave some damage to the paint on the floor, especially the passenger side tunnel edge.  I'll probably stick some heavy duct tape down on the edge just before removal and cover the floors with a moving blanket.  Once it's laying on the passenger floor, you just need to be careful going over the door sill.  It's the initial separation and rotation under the dash that worries me.

I’ve pulled/installed wayyyy too many boxes in Triumphs... put a moving blanket hanging over the sill and into the tunnel hole. Will definitely cut down on any scratches or damage.

FWIW, my new engine (started Thanksgiving week) now has about 900 miles on it. So far leak free - except a couple drops after every other drive or so. Only oil I can find is on two of the rearmost oil pan bolt heads, and the rearmost flange of the oil pan. Makes me wonder if the brand new rear main seal is leaking? I know my engine has the infamous copper washer, all bolts got thread sealant at the rear, and the core galley plug got a smear of sealant as it went in as well.

oppositelocksmith said:

I’ve pulled/installed wayyyy too many boxes in Triumphs... put a moving blanket hanging over the sill and into the tunnel hole. Will definitely cut down on any scratches or damage.

FWIW, my new engine (started Thanksgiving week) now has about 900 miles on it. So far leak free - except a couple drops after every other drive or so. Only oil I can find is on two of the rearmost oil pan bolt heads, and the rearmost flange of the oil pan. Makes me wonder if the brand new rear main seal is leaking? I know my engine has the infamous copper washer, all bolts got thread sealant at the rear, and the core galley plug got a smear of sealant as it went in as well.

That's the plan.  I also acquired a temporary Allen socket drain plug that will be more flush with the bottom of the gearbox.  The magnetic plug gets caught on stuff while dragging the gearbox out from under the dash.

Good to hear that the rebuild went well.  They all leak some oil, but I'm afraid mine will eventually end up on the clutch.  Funny thing, the clutch noise went away, but probably not forever.  Another theory I had was that the catalytic converter is heating up the gearbox more causing pressure in the case and forcing out some oil.  I used the Brad Penn GL-4 transmission oil, and it's a lot like the Brad Penn "green" engine oil.  I guess we'll see soon enough.

On the forcing out some oil thought, does your box have the 1/16” vent hole in the top cover? Should be on the front left top. 

I was reminded about mine when I went to store mine on the bellhousing end during the rebuild and came back to a puddle with a guilty trail up to the hole! 

oppositelocksmith said:

On the forcing out some oil thought, does your box have the 1/16” vent hole in the top cover? Should be on the front left top.

It didn't before I rebuilt it, but I drilled one.  My first TR6 had the vent hole plugged with something that looked like a miniature golf tee.  Supposedly a professional shop did a rebuild on it.

I'll pull the gearbox on Thursday.

The gearbox came out in 5 minutes, and that includes taking out the last two studs on top.  Putting in a flush drain plug helped it from getting caught on the floor.  I did need to pull the rear mount to make enough room as the top of the flange hit the firewall if it was jacked up enough to clear.  There's a little bit of oil in the bell housing, but not enough to account for the entire leak.  Pulling the clutch and flywheel tomorrow.

I'm glad it came out pretty easily.  Good luck tomorrow - I hope you find a super-obvious leak.  Preferably on a part where you already have a spare on the shelf!

TVR Scott (Forum Supporter) said:

I'm glad it came out pretty easily.  Good luck tomorrow - I hope you find a super-obvious leak.  Preferably on a part where you already have a spare on the shelf!

Ditto

There doesn't appear to be any major leaks coming from the gearbox.  I pulled off the cross shaft and saw very little oil coming from the countershaft plate and front cover.  Both were removed and resealed with new gaskets and RTV just to be sure and to look at the back of the front seal.

Next was the clutch.  It's dry, but there is some wear on the fingers.  Too much for just 50 miles, so I'll try a spring to hold the throw out bearing against the fingers.  The bearing is still fairly tight and it appears easier for the metal face to spin across the fingers with no spring.

Dropping the flywheel tomorrow and hopefully finding the leak.

Fingers-crossed for the rear main...