ShopTalk Forums | Aircooled VW Tech & Restoration Help

Oil passage size of these T1 pumps are bigger than the oil passages of the case. I've seen some articals showing the case getting opened up a bit to smooth the transition from the bigger holes of the pump body to the case size. I know the holes don't line up so its not a simple matter of drilling the case bigger will need some offset grinding. Also heard of passageways getting drilled out bigger.

I didn't see much talk here about this issue when I did a search nor on the TIV video. Are case mod required? Pump is a modified 26mm unit from the TIV Store going into a 1.7L case warmed up to 2L for my bus

Use a die grinder, drill motor, Dremel, etc and a suitable burr and open up the case passages to the line that you scribe thru the holes in the pump. Blend up the passage 1/2-1" and that's it.

I'm assuming since you use the term "passages" both the inlet and outlet get opened up to match the pump.

This is not a requirement, as the pump will work just fine without doing any mods at all, BUT it's always best if the passages align perfectly with any pump.

Tom's metod is the way to get them aligned...

Thanks for the info. I was going back and forward in my head thinking it does/doesn't make a difference. Have the tools already and did the outlet side last night, smooth operation so onto the inlet side.

Put your pump in the case half and scribe the missallignment with a sharpend nail. Then grind it out.