I have a transmission question Wednesday, 05-Jul-2000 14:22:43 Message: writes: Someone told me that they took a 3.88 ring and pinion from a 1974 IRS transmission and installed it into a swing axle without machining it. Is this true? I thought that the pinion is too big for the swing axle transmission and that it needs to be bored out? I appreciate any info on it. Thanks! Paul Paul

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The 3.88 R&P will fit. Depending on the vintage of your present box, 4th gear may have to be swapped for a splined unit. (n/t) (Dougy Dee) (05-Jul-2000 15:37:04)

Re: I have a transmission question (Gary Cooper) (05-Jul-2000 18:14:25)

Thanks guys that helps out a lot. My current transmission is 1963, will this still work? (n/t) (Paul) (06-Jul-2000 09:38:24)

If you're going to build a trans for HP use, start with something newer (Bruce Tweddle) (06-Jul-2000 20:57:15)

Paul Bruce has the right idea just as long as the irs has two side covers that are removable. (n/t) (Gary Cooper) (07-Jul-2000 00:26:52)


Re: I have a transmission question

Wednesday, 05-Jul-2000 18:14:25 writes:


3.87 R&P will fit earlier gear boxes with a few changes.

The machining everyone is talking about is on the main shaft for same box you are talking about is because of the close ratio gears for 3&4th are early style gears and require the keyed hub , the late models use an larger splined hub and a split type bearing.So the spline and 4th gear inner race (which is part of the mainshaft)must be removed and then early keyed hub and 4th gear inner race pressed on.

The 3.875(3.88) R&P uses an splined 4th gear rather than the early keyed type and also has snap ring on end rather than hex nut. your old 3rd gear will work however 4th wont unless from (im not sure about this )lets say 70 1/2? to 72 1/2 yr gear box which would be irs like I said im not sure about those years but im close.

I tried to explain without getting to indepth but I hope this Helps.


Gary Cooper


If you're going to build a trans for HP use, start with something newer Thursday, 06-Jul-2000 20:57:15 writes: Year by year, VW made improvements to the transmissions. By starting with a newer trans, you take advantage of all these improvements. For example, the shift rods which ride in the gear carrier on all years also ride in the main case on later transmissions. Your early box will not have this improvement. Some say the best starting point for HP swing is a 72 IRS trans converted to swing. Bruce Tweddle


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