37 replies to this topic

[Spider]

Wonder if you could make up a spacer to move the seal to run just out of the groove?

 

Don't shoot, just thinking aloud!

 

Shoot ?    Bhahahaaha,,,,,,,

 

In a pinch you could, but it would be a stop gap rather than a repair / permanent solution. Remember here too, there's 3 - 4 (or even 5) thousands end float on the crank and 3 to 6 on the Primary Gear, though that quickly increases to 10+ with the soft C clips, so it's not out of the question to have 20 thou (or 0.5 mm) end float as seen by the seal here.

[Ethel]

I confess I hadn't even thought of end float, more occupied by if the seal would end on rubbing on the clutch or just fall out of the tranny casing.

 

Gaining a millimetre wouldn't seem out of the question, maybe more if you resorted to gluing it in its 'ole

 

   (closest we have to a shameless botcher smiley)

[JonnyAlpha]

You don't have to run the new seal on that groove. The seal track seems rather a long way in anyway, meaning the seal may have been fitted too far in.

There's plenty of engines get built with the seal fitted in such a way as to be running on an un-worn part of the seal surface.

Just another ( and cheaper) option 

 

Out in the garage this afternoon trying to see whats what regarding seal positioning.

 

Crank - Bushing - Primary Gear - Orange Seal in Transfer Case

 

If the seal is fixed in the Transfer Case how do you adjust its position in relation to the Primary Gear?

[imack]

The primary gear oil seal is set into the transfer case using this tool. It fits over the crank taper and is pulled down with the flywheel bolt. It sets the seal about 60 thou below the surface of the transfer case face.
I think people are suggesting you don't set the seal so deep in the case.

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Edited by imack, 14 April 2020 - 08:39 PM.

[JonnyAlpha]

So the seal is installed after the Transfer Case is bolted to the GearBox / Block. And you use the Flywheel Bolt to tighten down that tool which pushes the seal into the transfer case.
But rather that seating it full home leave it a fraction less? (In theory)
Looking at the mark on the primary gear it must be caused by grit or metal filings stuck between the seal and the primary gear?
The seal has some flexibility around its inner edge that fits on the seal surface which may still make a seal.

 

I wonder if some sort of spacer under the seal would work to hold it in place?

Edited by JonnyAlpha, 15 April 2020 - 01:30 PM.

[ACDodd]

I have another batch of them in this week for bushing.
The seals are destined for a seal diameter of 54.8mm. The gears when new are 55mm. It's perfectly possible to grind a the surface down to remove the wear. The gear second from the right in the image below had a burnt and scratched surface. I simply reground it 0.002" undersize this week when setting up my own regrinding tooling and it's now good to go again.
It's also possible to refit the seal and leave it's front face proud of the housing by about 1.5mm this ensure the new seal runs on a different part of the primary gear seal surface.

The second image shows a couple of tester grinds.

Ac

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Edited by ACDodd, 15 April 2020 - 10:34 AM.

[ACDodd]

See here for more info;

https://m.facebook.c...100003311020189

[Ethel]

So maybe the best option is to reposition the seal, if you can. Then you'd still have the option to regrind when you've gotten another 20 years out of the gear 

[JonnyAlpha]

I have another batch of them in this week for bushing.
The seals are destined for a seal diameter of 54.8mm. The gears when new are 55mm. It's perfectly possible to grind a the surface down to remove the wear. The gear second from the right in the image below had a burnt and scratched surface. I simply reground it 0.002" undersize this week when setting up my own regrinding tooling and it's now good to go again.
It's also possible to refit the seal and leave it's front face proud of the housing by about 1.5mm this ensure the new seal runs on a different part of the primary gear seal surface.

The second image shows a couple of tester grinds.

Ac

 

Thanks AC all a little clearer now

 

So maybe the best option is to reposition the seal, if you can. Then you'd still have the option to regrind when you've gotten another 20 years out of the gear 

 

Sounds like a plan

[JonnyAlpha]

You don't have to run the new seal on that groove. The seal track seems rather a long way in anyway, meaning the seal may have been fitted too far in.

There's plenty of engines get built with the seal fitted in such a way as to be running on an un-worn part of the seal surface.

Just another ( and cheaper) option 

 

 

Wonder if you could make up a spacer to move the seal to run just out of the groove?

 

Don't shoot, just thinking aloud!

 

Yesterday I spent some time trial building the associated parts to understand how it works, what causes the issue and try and work out exactly what @Pigeonto and @Ethel mean?

 

I now have a better idea and can see that if it is possible (as mentioned) that if the Red / Orange Primary Gear Oil Seal could sit a little further out in the case, then this would move the sealing point to a different position on the Primary Gear thereby stopping any oil seepage.

 

At first I couldn't work out how you would get the seal to sit on a different position and with regards to a spacer I thought @Ethel meant putting a spacer on the Primary gear itself to sit just behind the seal.

 

I now understand that you just don't knock the seal in as far when inserting it (as illuded to by @imack), the problem is this is not an exact science as a tap too much and bang in it goes leaving you to have to try and pull it out a bit. This I guess is where the spacer idea comes in. If I could (or get) fabricated a washer of the appropriate thickness to sit in the recess in the transfer case behind the Primary Gear Oil Seal. This would enable you to tap in the seal and the spacer would ensure that it sits proud the correct amount.

 

Thoughts?

[DeadSquare]

Welcome to the "Bodger Brigade".

 

If you grease / oil the seal and the housing, you can push the seal in with your thumbs.

 

If you think it is in too far, with a blunt screwdriver, you can tap it carefully back.

[Ethel]

I confess the spacer thing was a bit of a brain fart. It's been a few years since I've had one in bits so it slipped my mind there's not the usual counter bore to seat the seal against & keep it square because the hole's designed to fit the primary gear through too.

 

There's nothing in the transfer casing to fit a spacer against to keep the seal farther out of the hole. You could make one to sit around the hole to aid you in seating the seal square and the thickness of the spacer proud of the casing, but a washer of a suitable thickness and a straight edge would do well enough to check the depth of fit is even on all sides.

[JonnyAlpha]

Just resurrecting thus post to ask an associated question.

 

If I decided to replace the Primary Gear, it has been suggested that the Drop Gear set (Primary, Idler and Input Gear?) should all be changed together to avoid a noisy gearbox?

 

I also see that Primary Gears for the 1275 A+ come in two sizes (29 and 30 tooth and these and drop gearing comes in various flavours, Economy and Standard?

 

Can someone clarify the different setups?

 

The diff was a 2.95 but I have now swapped this for 3.44 Diff. With my existing drop gear setup (which I believe is economy), the change to the 3.44 Diff will be a good option, however if I decide to change the Primary gear (and maybe the drop gears in thier entirety) what should I choose? 

The Engine will be a 1310, AC RS Cam, Std Head (for now), HIF 44, Stage One Kit.

 

Using John Guess's Gearbox and Speedo Ratio Claculator, this is (I believe) my proposed setup if I keep the same Primary / Drop Gears.

 

 

 

TVM 

Edited by JonnyAlpha, 11 June 2020 - 06:46 PM.

[JonnyAlpha]

Anyone?

[duffdub]

I think my primary gear looks okay? Any input? The bushings do need to be replaced, what would cause these markings?

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