Type 1 Trans. Modifications

Joe Locicero of Oregon Performance Products recommends the following Type 1 transmission modifications when using a Type 4.

"Use a super-dif, H.D. side cover and have the engagement teeth welded on third and fourth gear. On the '71-up trans case, use an asymetrical bearinged Vanagon pinion bearing.(Same I.D./O.D. as T-1 unit) Transmission straps are out. Use a rear engine hanger with the stock rubber mounts- unless your racing. This results in five insulated drive train mounts. Best ratios found for Type 4 in Type 1 is a 4.125 R&P with a .821 4Th gear with a final drive ratio of 3.38:1. In a Type 4 in a Type 2 (early) is a 3.875 and a .89 4th with a final ratio of 3.44."

This will make the Type 4 a nice freeway cruiser. If you are interested in more performance (as in drag racing), try sticking with the stock 4th gear or go to closer ratios to minimize the RPM drop from 3rd to 4th gear. The extra torque of the Type 4 makes the use of ultra close gears like with a Type 1 unnecessary.

The above applies to '71 and later Type 1 transaxles with the guided throwout bearing. In the '67-'70 type 1 trans, the trans can be made to appear like the '71- up by changing the throwout cross shaft to a '71 Type 1 only throwout cross shaft. The sleeve on the input shaft is available from Carter's gear box shop in Big Bear, CA. The input shaft seal is removed and the sleeve is driven into position over the input shaft. The sleeve has an internal oil seal. Now the bell housing looks like a '71-up. Some have suggested the use of a Type 2 IRS input shaft in the Type 1 transaxle to get the longer shaft, but the larger area differential area of the Type 2 transaxle makes for a longer input shaft overall. In other words, the shaft is too long and will not work.

Thanks to Joe Locicero of Oregon Performance Products for the wealth of information concerning the use of a Type 1 transaxle and a Type 4 engine.