Differences between parts 139208 and 139210

They have a different number of teeth (and slightly different diameters) so are not individually interchangeable. 139208 is for a euro version without cats and has an overall drop gear ratio of 27/29. 139210 is for a C8 or CAT version (which both have cats) and have an overall drop gear ratio of 26/27. Since the center distances between the gears is fixed for all versions, you need a complete matching set of gears 3, 4, and 5 (as labeled in the SPC) for each different drop gear ratio. The drop gear ratio for any specific year/version TR is shown in the OM for that year/version TR.

 

"AMEN!" to that

Since the euro is 27/29 and the US is 27/30, they both use a 27 tooth drive gear (but I would've thought the diameters and tooth shape would be just slightly different). Your car certainly meets the (only) SPC stated requirement for 139208 being above SN 80177, and there's no other US specific drive gear given for your SN so can't say that it isn't right for your car. However, drive gear 138384 also seems right for your car so maybe they just forgot to label one for "standard/euro" (which they usually leave unlabeled) and the other one "for US"? I can say with somewhat more certainty that you couldn't use 139210 as a substitute for 139208 as 139210 only has 26 teeth.

What are you up to? Did these gears get damaged?

 

Pretty sure it will have to do with the pitch diameter of the gear and gear module (the size of the teeth). The usual design process is that you pick a (standardized) gear module, which determines the pitch diameter of the gears for the gear ratio you want, and then this determines the center-to-center distance between the gear axes. If you change the gear ratio = the center-to-center distance changes (when you keep the same gear module). In this case (with fixed center-to-center distances), when you want to change the ratio = you'd need to change the gear module (to something non-standard) which also changes the pitch diameter of the gears.

 

I watched the video of what your gearbox was doing and what the cause was. Has anyone else seen this failure? It seems odd and rare.

 

what video? link?

 

thank you
this I never had seen before

 

I'm going through a similar circumstance with my 1990. I have the clutch input shaft is 138383 part number and my drive gear is also 139208

I purchased a used set of good gears and the drive gear on this set is 125262 which has a sleeve on the end and thus does not fit this input shaft.

 

The problem is that the new drive gear that I have where the input shaft goes in has the neck on it on BOTH sides. So when you put the shaft through, you cannot get the nut on it with the other side.

Clutch shaft 138383 will not fit this gear that I have which is 125262. 139208 has no neck on the side where the clutch shaft inserts.

Are you telling me that you got the nut secured as shown below in your photograph?

 

Okay so where on earth did you find the correct bearing for the shaft???

the 103042 bearing is too wide for the 123810 shaft. It will fit my original shaft which is the 138383 but then the 138383 shaft will not fit the older gear set which has the 125262 gear because it has a neck on it and you cannot get the nut attached to the other side. Where did you find this bearing??

Or are you saying that you replaced your gear with the 138384?


Or am I just using the wrong nut?? This is nuts LOL