Ring and pinion question.

C

Coupe35

Senior Member
What happens when a ring and pinion from two different sets are used together. If it is noise, is there anywhay to fix the problem.
 
I can't recommend it nor would I do it but and old timer I knew in Missouri used to lap gear sets in using valve grinding compound. His Ruxtells (T-Model) were super quiet. I don't remember his procedure. I would imagine he cleaned the heck out of everything before the rear end went into service. I hope someone chimes in with an alternative solution! Dennis/Arkansas
 
I would like to know the factory procedure for matching gears and pinions. Did some poor soul spend his entire day lapping or somehow making matched sets?

I'm mindful of the old factory system for balancing cast steel crankshafts, the first crankshaft was balanced and subsequently every crank was drilled in the same spots to the same depth, the theory being that every crank poduced from the same mould would theoretically be the same, minor differences accepted.

Using the same theory I assume that each gear and each pinion produced are identical, and that someone would pick one of each from an assembly line and package them as a set. At the price a set can be bought for I don't see how any labour could be factored in for a skilled technician to spend any time at all to "match" pinions to gears. Unless the only matching involves the counting of teeth.
 
Fe26 said:
I would like to know the factory procedure for matching gears and pinions. Did some poor soul spend his entire day lapping or somehow making matched sets?

I'm mindful of the old factory system for balancing cast steel crankshafts, the first crankshaft was balanced and subsequently every crank was drilled in the same spots to the same depth, the theory being that every crank poduced from the same mould would theoretically be the same, minor differences accepted.

Using the same theory I assume that each gear and each pinion produced are identical, and that someone would pick one of each from an assembly line and package them as a set. At the price a set can be bought for I don't see how any labour could be factored in for a skilled technician to spend any time at all to "match" pinions to gears. Unless the only matching involves the counting of teeth.
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I built front and rear axles for Chrysler for 15 years, both chrysler corprate, and all of the Dana axles. Every gear set comes with an hand engraved code number, onced the pinion and ring gear are matched.....Ed
 
34fivewindow said:
I built front and rear axles for Chrysler for 15 years, both chrysler corprate, and all of the Dana axles. Every gear set comes with an hand engraved code number, onced the pinion and ring gear are matched.....Ed
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Thankyou, but how are the sets matched, tooth count or lapping etc.
 
Fe26 said:
Thankyou, but how are the sets matched, tooth count or lapping etc.
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Each ratio has it own tooth count, but the lapping is done by machine. Once they are matched, and inspected by the Tech, they are hand engraved with a code number......Ed
 
Coupe35 said:
What happens when a ring and pinion from two different sets are used together. If it is noise, is there anywhay to fix the problem.
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I have always kept R&P gears in their original matched sets as they were matched at the factory. However, I have heard tell of others, I believe Fordbarners, who have mismatched them on occasion and it worked OK for them. Maybe this was done out of necessity to get their car back on the road or track quickly and they had no other choice. Maybe they were also lucky :). J.M.
 
I have also heard of mismatched gears being used with success. I am positive that the factory did not lap the gears--too much time and expense. These axle assemblies are very simple and lots of people over think them. When the assemble is put together and hand turning with out too much pressure is experienced most of the time the result is good and quiet. Dial indicators and micrometers are overkill!!
 
Jerry Grayson, don't be so positive about the factory NOT lapping the gears and retainin them in sets. The following is about to change your thoughts. I have copies of some original Ford Motor Company ring & pinion blueprints from the early thirties. The following image is from the lower right corner of the blueprint. It very clearly states that the ring & pinions will be lapped and kept together as a set. This note is on all of the blueprints that I have. If you mix and match a set, you may get lucky and not hear any noise. But I'd change the gear oil quite often while the ring & pinion "lapped-in" while driving. Regards, -Mike :)
 

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Well, let's try the image again and hopefully it will be large enough to easily read. -Mike
 

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Mike34 said:
Well, let's try the image again and hopefully it will be large enough to easily read. -Mike
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Mike, I appreciate the information. I suppose that the image is an engineering drawing and this is what the designers desired, however I am skeptical if the vendor actually did this.
 
Yes, the manufacturers lapped and matched all ring and pinions and kept them together until assembly. The machining tolerances were not nearly as precise as today so this was imperative to prevent gear whine and even then it wasn't unusual to hear gear noise in a new car. This would never get better, just louder until you couldn't stand it and had it repaired.
 
There has just been a thread in the Model A forum on exactly the same topic, with much the same results although a few more "yes" replies. It seems that you can do it OK, but you will take the chance on whether or not it is going to be noisy. I would agree with the previous poster who suggested frequent change of oil initially until the parts settled in.
In this part of the world the parts are becoming increasingly hard to find, and this scenario may crop up more often as time goes by.
 
There have been many discussions on the Barn over the years where someone will post casting doubt on the necessity of following the procedures that Ford specifies in its Service Bulletins and advocating "short-cuts." My experience has been that if those procedures ARE followed, the result is very good, whereas the results of NOT following them makes the reasons FOR following them quite evident.

The quality and consistancy of Genuine Ford Parts is nothing short of amazing.
Ford cautioned against using "spurious parts" for good reason. We are now left to have to deal with "aftermarket" stuff, where there is often little or no quality, and no quality CONTROL. It is especially important when installing
after-market rear end gears to have a dial indicator, micrometer and a device
for measuring the preload on pinion bearings. Otherwise, it is just a crap-shoot, with the possibility (probability?) of having to do the job over.

Overkill beats the hell out of underkill...
 
Richard (EV8G) said:
Overkill beats the hell out of underkill...
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WELL SAID;

It is WAY too much work to go thru a rear end and use questionable parts only to find you have to do the job all over again.

Unless you have a bunch of time on your hands and do not mind having to do the job over, Do it right and Do it once.

My Opinion;

Chris
 
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