Mb / Bf / Frog Gearbox : Re-re Frog Compatiblity

[Black Hole Sun]

Hi all !

As many owners I guess, I have a problem with my Monster Beetle gearbox

I would like to reinforce it, or to use the re-re Frog chassis series to change it.

Problem is to determine the level of compatibility between all those gearboxes.

Here is the original MB / BF / Frog / Brat gearboxes (here from the MB manual):

Here is the re-re Frog series gearbox (here from the re-re Subaru Brat manual):

1st question : are they strictly identical?

For me, they are not. The re-re Brat PG1 2 ou 3 intermediate pinion is different form the MB's (setp 18) because there is this MD3 pinion that has to be inserted inside the re-re one's. Your opinion ?

2nd question : is the MB gearbox (I mean the big C16 plastic part + the metallic plates) strictly identical with re-re frog series' ? Question is : will they fit in my MB chassis ?

3rd question : is it possible de reinforce all the pinion fixations inside the originale gearbox ? How ? I don't want to change it for the Thorp diff that was mainly used by the time and difficult and expensive to get nowadays.

I ask the question to goldstarskockists and here is their response :

The gears inside the Frog gear box have not changed with the reissue, so if it is just the drive shafts that are worn you need:

9808037 Gear Box Joint (pair) for Frog 5.50

9808039 Wheel Axle for Frog (pair) 6.50

9808038 Drive Shaft for Frog (pair) 4.25

If the splines where you push the gear box joints into the gear box are

damaged then you need:

9440510 Bevel Gear Bag for Frog 2.99

Of the other parts:

9005139 are the plastic gears

And for the pinions, you would normally run the 16t pinion in the Monster

Beetle.

The only other part to check when you reassemble is the metal gearbox outer plates - these can bend outwards around the diff but can be reshaped.

If I correctly read the first part : everything is the same (uh ?!) but dogbones are different (I agree).

For the "splines" part, I don't understand what they are talking about.

I understand the end of the message : they recommend the 16T pinion and I have to check my metallic plates.

Thanks a lot for your kind advices.

[Shodog]

the splines are on the outdrives that slide into the lager bevel gears on the diff. I think you will be fine with the re-re stuff, although you should match up the blackfoot spur and counter gear with the re-re parts to make sure the two gears have the same amount of teeth.

[Black Hole Sun]

the splines are on the outdrives that slide into the lager bevel gears on the diff. I think you will be fine with the re-re stuff, although you should match up the blackfoot spur and counter gear with the re-re parts to make sure the two gears have the same amount of teeth.

Ok, so the splines are the B1 plastic pieces

Thanks for your answer

[Blacque Jacque]

Ok, so the splines are the B1 plastic pieces

Thanks for your answer

No no , the splines are the "grooves & ridges" on parts SA9 (the outdrives Shodog referred to) and SA6 / SA7, which are the larger bevel gears.

The B1 parts are the small plastic end caps on the intermediate gearbox shaft.

[Black Hole Sun]

No no , the splines are the "grooves & ridges" on parts SA9 (the outdrives Shodog referred to) and SA6 / SA7, which are the larger bevel gears.

The B1 parts are the small plastic end caps on the intermediate gearbox shaft.

OK, the B2 parts.

Sorry my English is not that good, in particular for technical matters

I'll go for an entire re-re frog gearbox (inside elements) and shafts : I'll be sure to have everything, and spares.

Thanks a lot.

[Blacque Jacque]

Sorry my English is not that good, in particular for technical matters

No apology needed . I did not mean to criticise your English, only to make sure you have the correct part number.

[Black Hole Sun]

No apology needed . I did not mean to criticise your English, only to make sure you have the correct part number.

I know you were not criticising me, but I also know my English skills are limited That's why I don't participate that much to this great forum

Thanks again for making sure I have the correct part number.