AQ 275 o/d u-joints and upper gear housing

[Zeker]

I need to change the u-joints on my AQ 275 coupled to a AQ 131-A 2.3L '86 Bayliner. I removed the upper gear housing and found that two of the four allen head bolts securing the drive shaft will not release. I went as far as drilling the heads off the bolts and heating the sides of the casing until the penetrating oil boiled and it still won't release. Any ideas? If I have to replace the entire upper gear housing what o/d models will have usable upper housings?

 

[PiratePast40]

Re: AQ 275 o/d u-joints and upper gear housing

I made the mistake of doing something similar with mine. I even went so far as taking it to a machine shop and they milled too much off of the bolt head seating surfaces. That area is a pressure boundary so the clamping ring was ruined.

I don't know of any magic incantation to remove the bolts but I did take mine to a retired Volvo Penta technician and he was able to do the repairs. The gearboxes off of the 270 and 280 are also essentially the same. If you go for a replacement gearbox, try to get one from a 4 cylinder since it should have less wear and tear. Might want to check out ebay for a clamping ring.

 

[Zeker]

Re: AQ 275 o/d u-joints and upper gear housing

Thank you for your help. I notice there is a lot of pitting on my 275. Is there much advantage (and hopefully a minimum of work) to upgrading to a 280 or a later o/d?

 

[Don S]

Re: AQ 275 o/d u-joints and upper gear housing

The 280 will fit as long as you have the same type pivot on the helmet attaching bolt to the drive. You could have a single bolt, or a pivot and 2 bolts. The upper gear box is different for each.