BJ8 Transmission just rebuilt now has metal filings

[AUSMHLY]

Gents, I just had my BJ8 rebuilt and installed in the car.
Issue was hard to get into 2nd. Mechanic replaced these parts:
Laygear, AHSpares remanufactured one piece (not the used OEM laygear where 1st gear is welded on)
2nd gear, used in excellent condition.
1st motion shaft bearing new
Mainshaft bearing new
Synchro rings, 2,3,4 Denis Welch new

I was with the mechanic providing what ever help I could.
We found the Laygear from AHSpares was too long to install. The front and rear Thrustwashers were filed down enough so the Laygear would go in. Front ended up being thinner, flush with the Thrust plate. The rear was thicker but wasn't filed evenly. You could see it was thicker on one side once on the Thrust plate. Ask the Mechanic if that's an issue, he said it should be fine, there's about 0.0012 endfloat.

When assembling the OD, the shim bearing was missing. With the OD gasket on, he measured the size needed and add them.

Rebuilt in, fiberglass cover off (I've had this tranny in/out so many times, I end up testing it with it off, so I know how loud the gears are with it off) the sound of the gears are louder then I've ever heard. It shifts better into 2nd then it ever has, but shifting into all gears is not easy, smooth flowing like other BJ8's I've driven. It seems like I'm shifting without oil. 2nd gear is loudest and gets louder when I take my foot off the gas as the car slows down. I also smell a sort of burning smell after about 1/2 hr. (The engine was rebuilt and has about 200 miles. It maybe from the engine? No tranny cover. But want to point the smell out because to the loud gears).

I drained the oil. Findings were, metal filings on the magnetic drain plug, small pile of bronze in the bottom of the tranny. I painted the internal case with Glyptal Red paint and all gears where cleaned. I see debris in the oil, some looked like gray RTV which I believe was coming from the OD. (I used blue Hylomar.) The OD was working fine so I didn't touch it.

I removed the transmission and brought it back to the transmission mechanic.
I asked if the laygear maybe the issue. He said it shouldn’t because it spins and has endfloat.
While on the bench, top off, he could move the reverse fork with his hand.
1/2 fork he needed to tap a screwdriver to move it.
3/4 was harder to move with a screw driver. Once in 4th, it was stuck, very hard to move back to neutral and needed to hit it harder.
He said put the tranny back and let me drive it. I'm nervous about driving it to him, with what I've described.

I'm trying to figure out what is causing these issues.
I watched a Youtube BJ8 rebuild by Magnus Karlsson “Boras” where he places the 1st gear assembly on the main shaft then says “ Here come the spacer ring which is very important but can easily be forgotten”. (Is the "spacer ring" is also called the “distance collar” ?)
I don’t know if the spacer ring was installed. What happens if I don’t have it? Should I? The AHS diagram (color) doesn’t show it. The Moss does.
Could that be the cause of hard shifting and loud gears?

Could it be bad/bent selector shafts for the hard shifting?
What's causing the metal filings? No spacer ring?
Could it be the Laygear? Should I replace it with the rebuilt welded ones and replace the front and rear Thrust plate and Thrustwashers with new?

 

[Bustren]

Hi Obi Wan
I will give you some comments.
1. A laygear endfloat of 0,0012 (0,03 mm) is in my view too small and was it measured when the OD and clutch housing was mounted? I set 0,2 mm in mine and with tight shims setting on the input and main shaft bearings was it reduced to 0.15 mm when the OD and clutch housing was mounted. 0,15 is absolute minimum for me. Or was it 0,012 you meant ?
2. There are 2 steel balls between the shifter shafts. When I mounted new shafts I had to very slightly adjust the groove in one shaft, it was too tight. Make sure they can run smoothly without forks mounted. If needed to adjust, make sure you don’t overdo it, the balls are there to make sure only one gear can be engaged at the time.
3. In the coupling sleeve of 3-4 you have 2 small pins. In mainshaft splines you find 2 cut outs that these pins must match. Furthermore there are 2 cut outs in the outer sleeve engaging teeth’s that shall match these pins. If not correct mounted will engagement of 3-4 be difficult. What you describe indicates wrong positioning, I know from experience.
4. I had a new gasket between the gearbox and OD that was 0,25 mm thicker than original, I added an extra 0,3 mm shims for the bearing. Measure what shims is needed for both main bearings, take the thickness of gasket in account. Seems though you have done this.
5. Needle bearing inside input shaft missing can cause problem with parts interfering
6. I would take the gearbox out and take it apart.
Brg

 

[gonzo]

Sorry for your transmission woes. Since the trans is already removed from the Healey, your mechanic should be able to continue with bench diagnosis. Brass filings are from syncros; only metal filings (from gears, shafts and bearings) will attach to magnet. What appears on the mag drain plug is concerning.

Fortunately, there are options.

 

[AUSMHLY]

Hi Obi Wan
I will give you some comments.
1. A laygear endfloat of 0,0012 (0,03 mm) is in my view too small and was it measured when the OD and clutch housing was mounted? I set 0,2 mm in mine and with tight shims setting on the input and main shaft bearings was it reduced to 0.15 mm when the OD and clutch housing was mounted. 0,15 is absolute minimum for me. Or was it 0,012 you meant ?

Why does the Laygear endfloat get smaller when the Clutch Housing and OD get bolted on?

 

[AUSMHLY]

Hi Obi Wan
4. I had a new gasket between the gearbox and OD that was 0,25 mm thicker than original, I added an extra 0,3 mm shims for the bearing. Measure what shims is needed for both main bearings, take the thickness of gasket in account. Seems though you have done this.

Diagram show two shims for the front, two shims for the back.
Is one shim flat and one shim spring?

Where does one buy shims?
Moss, BCS don't list them for sale or N/A.

AHS sells only the front.
SHIM-front bearing (0.002')
SHIM-front bearing (0.005')

I believe the front and rear are not the same diameter so can't interchange.
I believe the shims are to keep the Mainshaft and 1st Motion shaft from having any endfloat.

What cause and effect would having too many shims cause?

 

[Bustren]

Here is example of measurement I made when rebuilding my gearbox (input shaft bearing, in mm).
The language is mixed, hus = housing, packning = gasket.
When the OD and Clutch Housing is mounted can geometry be changed, flat surfaces etc exist only in theory.
The earlier Healey gearboxes had a 1 mm deeper grove in housings where a preload washer can be used, BJ8 gearbox do not have this feature, I guess it was a rationalization.
When accelerating the helical gears will apply force pressing both main and input shaft bearings against the gearbox housing, de-accelerating the opposite direction but with much less force. Pre-load washers was not a bad idea, but the feature is not for BJ8 gearbox.
Correct that the part list has two shims, but quantity is set "as required"
Both bearings are in mm, easy to find suitable shims on the net. I have bearings 6307 (dia 80 mm) rear and 6308 (dia 90 mm) front, there are different qualities of these bearings, I bought from Denis Welch, are very good ones.

brg

 

[Zitch]

Did your oil look like this?

but if it's tough to shift..

After a break in you should have some filings

 

[AUSMHLY]

Did your oil look like this?

but if it's tough to shift..

After a break in you should have some filings

I've posted photos, pls see my 1st post.

 

[AUSMHLY]

Hi Obi Wan
I will give you some comments.
1. A laygear endfloat of 0,0012 (0,03 mm) is in my view too small and was it measured when the OD and clutch housing was mounted? I set 0,2 mm in mine and with tight shims setting on the input and main shaft bearings was it reduced to 0.15 mm when the OD and clutch housing was mounted. 0,15 is absolute minimum for me. Or was it 0,012 you meant ?

3. In the coupling sleeve of 3-4 you have 2 small pins. In mainshaft splines you find 2 cut outs that these pins must match. Furthermore there are 2 cut outs in the outer sleeve engaging teeth’s that shall match these pins. If not correct mounted will engagement of 3-4 be difficult. What you describe indicates wrong positioning, I know from experience.

Thank you for your help.

Sorry, I need to make a correction.
1. I originally said Laygear end float about 0.0012. I meant 0.012

3. In the coupling sleeve of 3-4 you have 2 small pins. In mainshaft splines you find 2 cut outs that these pins must match. Furthermore there are 2 cut outs in the outer sleeve engaging teeth’s that shall match these pins. If not correct mounted will engagement of 3-4 be difficult. What you describe indicates wrong positioning, I know from experience.

This is a learn as I go.
The tranny is now on my bench and I'm trying to figure out the problems. The mechanic hints at driving the car to see if things work themselves in. I don't want to do that being I have metal filings and loud gear noise.

What is a coupling sleeve? Moss #25?
Are the 2 small pins called a plunger? Moss #29?
In mainshaft splines you find 2 cut outs that these pins must match. Moss #68/69 position?


Would you point out these parts in the attached Moss diagram.

 

[Bustren]

Hi
The 2 small pins are item 29 above.
The Photos attached shows details:
- inner hub has two radial holes for the pins
- outer sleeve has a recess made on the engaging teeth. The same is done on the opposite side matching the second pin.
- the main shaft splines has matching recesses for the pins.
This can only be assembled in one way to have the pin’s matching the recesses.

note that I have coloured the sync cone to check the alignment to sync ring by rotating the sync ring by hand.

 

[AUSMHLY]

Hello,

Today I took all the gears out to find out where the metal filings are coming from. I found 2nd gear has 6 teeth with a chip on the end. I'm concerned where those pieces are. I didn't see them when I drained the oil. Also the small teeth seem to be getting damaged.

The new laygear doesn't show any damage to any of it's teeth. I now know I have too much end float, measurement shows 0.015. I'll be correcting that to 0.012.

Would excessive Laygear end float cause the loud gear noise and damage to 2nd gear?

I also found 1/2 and 3/4 selector rods were bent and wear on 1/2, 3/4 shifting forks. That explains the hard shifting. (I'm replacing those)

Could that also be the cause of why all the gears sound louder?

What is causing 2nd gear's teeth to chip?