Crown wheel and pinion diagnosis

356 Porsche-related discussions and questions.
Message
Author
Kevin Gross
356 Fan
Posts: 18
Joined: Thu Aug 31, 2023 1:22 pm
Location: MA

Re: Crown wheel and pinion diagnosis

#61 Post by Kevin Gross »

Vic Skirmants wrote: Thu Feb 22, 2024 5:46 pm Kevin; did you happen to use the later wide driven gear in an earlier case? That will not work.
Vic, I am not sure what you mean by later wide driven gear. The transmission was original to and is used in a '62. Could you please elucidate? TIA!

Kevin

Jon Bunin
356 Fan
Posts: 1804
Joined: Thu Oct 15, 2009 11:06 pm
Location: Vista, CA

Re: Crown wheel and pinion diagnosis

#62 Post by Jon Bunin »

Kevin Gross wrote: Thu Feb 22, 2024 3:55 pmWhen I first used the WSM math, I ended up with first gear rubbing against the case: it was too close. Adding 0.30 mm to the math, and of course making the corresponding adjustment to the sized paper gaskets, corrected this problem.

- calculated setting dimension: 59.22 + 0.01 = 59.23 mm
- S4 formula: basic dimension - setting dimension = 59.80 - 59.23 = 0.57 mm --> use two 0.30 mm shims for S4, from the 741.302.297.xx set.
And this led to 1st gear rubbing.

I added 0.30 mm to S4, so used three 0.30 mm shims, which moved 1st gear away sufficiently. (Actually I used one each of the 0.25, 0.30, and 0.40 mm shims to account for the fact that they're a little thinner than nominal.) And I remeasured pinion depth to get it right.
Kevin, where did you place the shims in this situation? The shims shouldn't have any effect on the position of 1st gear.
By shims, I'm referring to the round metal shims normally placed against the pinion roller bearing, not to sized paper gaskets.

Update- OK, I understand what you did. You moved the whole cluster, including 1st gear, further back with an extra IP gasket, while keeping the pinion in the same position with the extra shim.
Your last sentence seemed to suggest that it was the shims "...which moved 1st gear away sufficiently".

Vic was referring to the wider 34-tooth driven gear, 12.4 mm versus 10.8 mm, that was first used in the '62 Super 90 transmissions, and eventually in all B/C transmissions.
The transmission case was made deeper for these wider 1st gears.
Attachments
DSCN6486.JPG
Jon Bunin

Kevin Gross
356 Fan
Posts: 18
Joined: Thu Aug 31, 2023 1:22 pm
Location: MA

Re: Crown wheel and pinion diagnosis

#63 Post by Kevin Gross »

Jon and Vic, thank you as ever for your knowledge and insights. Jon, yes, the whole stack moved back, including 1st gear.

Kevin

User avatar
Tom Markussen
356 Fan
Posts: 89
Joined: Mon May 12, 2008 11:43 am
Location: Denmark, Europe

Re: Crown wheel and pinion diagnosis

#64 Post by Tom Markussen »

Hi Kevin et al

Thanks a lot for the comment and sharing your experience. I am still waiting to receive the parts from Germany, but on its way. Will keep you updated.

Tom
Tom Markussen
1958 Porsche 356A Speedster T2 #83967
1958 Porsche 356A Coupe T2 #104598
1960 Austin Healey Sprite MK1 Frogeye #AN5/43259
1955 Alfa Romeo Giulietta Sprint #349

User avatar
Tom Markussen
356 Fan
Posts: 89
Joined: Mon May 12, 2008 11:43 am
Location: Denmark, Europe

Re: Crown wheel and pinion diagnosis

#65 Post by Tom Markussen »

Hi Kevin,

I can't find the reference to S4 in the Porsche manual. But I guess it is the same as no. "10" of the drawing which is the stack of shims?

Maybe S4 is mentioned/defined in the Hör manual?

Tom
Attachments
Gearbox drawing 01.png
Tom Markussen
1958 Porsche 356A Speedster T2 #83967
1958 Porsche 356A Coupe T2 #104598
1960 Austin Healey Sprite MK1 Frogeye #AN5/43259
1955 Alfa Romeo Giulietta Sprint #349

User avatar
Tom Markussen
356 Fan
Posts: 89
Joined: Mon May 12, 2008 11:43 am
Location: Denmark, Europe

Re: Crown wheel and pinion diagnosis

#66 Post by Tom Markussen »

Hi all,

The ring and pinion from Hör has arrived. Very nice machine parts -- but boring packaging/manual. They claim the shims shall be the same as standard 356B. I will make some measurements to be sure.

Tom
Attachments
Hoer1.png
Tom Markussen
1958 Porsche 356A Speedster T2 #83967
1958 Porsche 356A Coupe T2 #104598
1960 Austin Healey Sprite MK1 Frogeye #AN5/43259
1955 Alfa Romeo Giulietta Sprint #349

User avatar
Tom Markussen
356 Fan
Posts: 89
Joined: Mon May 12, 2008 11:43 am
Location: Denmark, Europe

Re: Crown wheel and pinion diagnosis

#67 Post by Tom Markussen »

For reference....

Fls = must be flankenspiel (backlash) = 0.17 mm
Attachments
Skærmbillede 2024-02-28 120222.jpg
Skærmbillede 2024-02-28 120148.jpg
Tom Markussen
1958 Porsche 356A Speedster T2 #83967
1958 Porsche 356A Coupe T2 #104598
1960 Austin Healey Sprite MK1 Frogeye #AN5/43259
1955 Alfa Romeo Giulietta Sprint #349

Jon Bunin
356 Fan
Posts: 1804
Joined: Thu Oct 15, 2009 11:06 pm
Location: Vista, CA

Re: Crown wheel and pinion diagnosis

#68 Post by Jon Bunin »

Tom Markussen wrote: Wed Feb 28, 2024 6:06 amThey claim the shims shall be the same as standard 356B. I will make some measurements to be sure.
Tom, let us know the measurement results of your pinion gears.
Kevin's HOER pinion measured 0.3 mm smaller than his original pinion, at 24.7 versus 25.0 mm.
Jon Bunin

User avatar
Jacques Lefriant
356 Fan
Posts: 4655
Joined: Mon Dec 06, 2010 1:50 pm
Location: Washoe county NV

Re: Crown wheel and pinion diagnosis

#69 Post by Jacques Lefriant »

Hi Jon
when i had the gears made they specified the MD(mounting distance). I suspect that initially the pinions were made for 84mm MD the calculation in the manual was made to determine the shim pack. Hoer 24.73+59.22+.02= 83.97 original 24.74+59.22+.01=83.97 i believe Tandler uses 84mm for their pinions also.
j
Last edited by Jacques Lefriant on Fri Mar 01, 2024 7:15 pm, edited 4 times in total.
 

Alan Klingen 2
356 Fan
Posts: 427
Joined: Fri Sep 15, 2023 8:20 pm

Re: Crown wheel and pinion diagnosis

#70 Post by Alan Klingen 2 »

Just off hand I would say the pinion was set too far into the ring gear. Alan The Stable.

User avatar
Tom Markussen
356 Fan
Posts: 89
Joined: Mon May 12, 2008 11:43 am
Location: Denmark, Europe

Re: Crown wheel and pinion diagnosis

#71 Post by Tom Markussen »

Hi Jon,

I managed to get the pinion shaft stack disassembled yesterday, without anything dropping out unintensionally. :)

The old and new pinion gear (axial height) seems to be very similar (24.73 to 24.74 mm). So not anything near 25.00 mm.

Old one: Made January 1966 (by Hurth)
New one: Made September 2021 (by Hör)

BUT what I discovered was that the pinion roller bearing has been spinning on the pinion shaft!! Not good, I am sure. So, good that I have already bought a new ring & pinion and a new roller bearing.

"Opening a can of worms!"

I'll keep you updated. Tom
Attachments
New old 01.jpg
Old01.jpg
New01.jpg
Old02.jpg
Bearing01.jpg
Tom Markussen
1958 Porsche 356A Speedster T2 #83967
1958 Porsche 356A Coupe T2 #104598
1960 Austin Healey Sprite MK1 Frogeye #AN5/43259
1955 Alfa Romeo Giulietta Sprint #349

User avatar
Tom Markussen
356 Fan
Posts: 89
Joined: Mon May 12, 2008 11:43 am
Location: Denmark, Europe

Re: Crown wheel and pinion diagnosis

#72 Post by Tom Markussen »

Hi again,

Interestingly, the profile of the old and new are different. Old one is more "pointy".

Fun to see so I will share with you all.

Tom
Attachments
New old 02.jpg
New Old 03.jpg
Tom Markussen
1958 Porsche 356A Speedster T2 #83967
1958 Porsche 356A Coupe T2 #104598
1960 Austin Healey Sprite MK1 Frogeye #AN5/43259
1955 Alfa Romeo Giulietta Sprint #349

User avatar
Jacques Lefriant
356 Fan
Posts: 4655
Joined: Mon Dec 06, 2010 1:50 pm
Location: Washoe county NV

Re: Crown wheel and pinion diagnosis

#73 Post by Jacques Lefriant »

Hi
they are different profiles the original is Gleason the Hoer is Klingelnberg
https://weddleindustries.com/sites/wedd ... d_Tech.pdf
j
 

User avatar
Jacques Lefriant
356 Fan
Posts: 4655
Joined: Mon Dec 06, 2010 1:50 pm
Location: Washoe county NV

Re: Crown wheel and pinion diagnosis

#74 Post by Jacques Lefriant »

Hi Jon + Tom
i redid the math on post #69 and i get 83.97 for MD for both.
j
 

Kevin Gross
356 Fan
Posts: 18
Joined: Thu Aug 31, 2023 1:22 pm
Location: MA

Re: Crown wheel and pinion diagnosis

#75 Post by Kevin Gross »

Tom Markussen wrote: Mon Feb 26, 2024 8:19 am Hi Kevin,

I can't find the reference to S4 in the Porsche manual. But I guess it is the same as no. "10" of the drawing which is the stack of shims?

Maybe S4 is mentioned/defined in the Hör manual?

Tom
Hi Tom, apologies, I am not always able to check all the forums every day! Yes, by S4 I am referring to item 10 in the drawing you posted: the 741.302.297.xx shim family.

I was intrigued by the last sentence in the instructions provided to you, in another of your photos. Clearly my experience was a little different, and the math needed some adjustment because of the different pinion heights. Maybe I missed something, I kinda doubt it, 1st gear sure was rubbing. But there are people on this thread with a heck of a lot more knowledge of the 741 than I will ever have. Cheers,

Kevin
23-09-13 050.jpg
23-09-13 041.jpg

Post Reply