Author Topic: Gear box carrier plate  (Read 770 times)

Sens

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Gear box carrier plate
« on: February 22, 2024, 22:18:58 »
Hello Pagode friends!

I have put the engine back in my Pagode and all went well!

I was going to mount the gear box carrier plate with the 12 M 10 bolts.
Quite an important plate since it supports part of the weight of the engine/ gearbox.

However I noticed that 4 of the bolts  had a bad thread and I was not able to tighten them. The steel is in good shape; not rusted or anything.
They must have been over tightened in the past I guess. I tried some new bolts, but same result.

Would a helicoil be the best solution to solve this problem?

Thanks for your advice!

Halvor Sens

Kevkeller

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Re: Gear box carrier plate
« Reply #1 on: February 22, 2024, 22:57:59 »
Did you try a rethreader or a tap in the nut ends?
1970 280 SL

Sens

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Re: Gear box carrier plate
« Reply #2 on: February 22, 2024, 23:05:59 »
No, I did not yet.

But would that "repair" the thread?
I am afraid I miss some metal in the tread.

I do have that M10 tap, but do you think that could help me?
It would be by far the easiest solution.

dirkbalter

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Re: Gear box carrier plate
« Reply #3 on: February 22, 2024, 23:07:59 »
If it is the bolts, you can just get new bolts. Cheap. In my case, the nuts that are tacked to the tunnel were bad and after re-tapping them, they would not allow me to apply torque without stripping. I had to replace 4 of them.
Dirk
66 230 SL
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53 CHEVY 3100
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Sens

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Re: Gear box carrier plate
« Reply #4 on: February 22, 2024, 23:12:18 »
Thanks for your comment!

In my case the problem is caused by 4 nuts, like in your Pagode, Dirkbalter!
And yes, I tried new bolts.
Putting new nuts is looks complicated; how are they accessible?

The helicoil solution could be a good alternative, I guess.

dirkbalter

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Re: Gear box carrier plate
« Reply #5 on: February 22, 2024, 23:20:08 »
They run along the left and right side of the tunnel bottom . With the carpet and insulation out, you should see them from inside the cabin. I was surprised how flimsy they were. After cutting them out, I tack welded regular M10 hex nuts in place, using the trans mount plate as a reference.
Dirk
66 230 SL
70 280 SEL
53 CHEVY 3100
18 C300 COUPE
05 HD FLSTNI

Sens

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Re: Gear box carrier plate
« Reply #6 on: February 22, 2024, 23:23:42 »
Oh! That is excellent news!

So they are accessible from the cabin after removal of the carpet and insulation! Fantastic!
That is a very good solution!

Thanks!

Pinder

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Re: Gear box carrier plate
« Reply #7 on: February 22, 2024, 23:27:28 »
could you use a larger tap and retap them?
1970 280 SL Light Ivory DB 670. 4 Speed manual shift no AC Limited Slip Diff.

Sens

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Re: Gear box carrier plate
« Reply #8 on: February 22, 2024, 23:31:21 »
Yes, but according to dirkbalter these are flimsy nuts, so making a bigger hole might be risky.

I think tacking new nuts in would be the best solution!


Pinder

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Re: Gear box carrier plate
« Reply #9 on: February 23, 2024, 03:06:36 »
That is true.  But maybe worth a try and if it fails then you can remove the carpet.

Regards
1970 280 SL Light Ivory DB 670. 4 Speed manual shift no AC Limited Slip Diff.

dirkbalter

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Re: Gear box carrier plate
« Reply #10 on: February 23, 2024, 03:08:03 »
These are the nuts I am talking about. You have to judge for yourself, but I had a hard time with the original ones applying sufficient torque without stripping them.
Dirk
66 230 SL
70 280 SEL
53 CHEVY 3100
18 C300 COUPE
05 HD FLSTNI

Pinder

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Re: Gear box carrier plate
« Reply #11 on: February 23, 2024, 03:11:40 »
Yes, probably best to take up the carpet so you have the same nut size.
1970 280 SL Light Ivory DB 670. 4 Speed manual shift no AC Limited Slip Diff.

Kevkeller

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Re: Gear box carrier plate
« Reply #12 on: February 23, 2024, 04:31:59 »
A rethreader is like a tap but the threads try to reshape the threads rather than cutting the threads.

https://a.co/d/2NV8geu

I’d try that first.
1970 280 SL

WRe

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Re: Gear box carrier plate
« Reply #13 on: February 23, 2024, 06:32:58 »
Hi,
one of my nuts which is tacked to the tunnel was also bad. As a quick solution I used a longer screw with an additional nut ontop to solve the problem.
Later I removed the flimsy nut and used the original screw with a new nut, although, as in the first case, this required a helping hand to hold it.
...WRe
« Last Edit: February 23, 2024, 06:38:30 by WRe »

Cees Klumper

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Re: Gear box carrier plate
« Reply #14 on: February 23, 2024, 07:42:46 »
I think replacing by tack welding new nuts is the best solution.
I suppose this also tells us these bolts really don't need to be tightened all that much.
Cees Klumper
1969 Mercedes 280 SL automatic
1968 Ford Mustang 302 V8
1961 Alfa Romeo Giulietta Sprint Coupe 1600
1962 FIAT 1500S OSCA convertible
1972 Lancia Fulvia Coupe 1.3
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stickandrudderman

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Re: Gear box carrier plate
« Reply #15 on: February 23, 2024, 09:30:48 »
Buy yourself a time-cert kit and do what any professional would do.
https://www.timesert.com/

Sens

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Re: Gear box carrier plate
« Reply #16 on: February 25, 2024, 19:41:22 »
I removed 4 bad nuts and replaced them by new ones tag welded to the floor.
Problem solved!

Thanks a lot for your support!

Halvor