interchangeable upper gearcase on 275T

[greeneyegi]

i need to replace the upper gearcase on my 87 capri with a 350 penta and 275t outdrive.their is an uppercase for sale on evilbay,he says its a"VOLVO PENTA UPPER UNIT FOR SP, 270, 280, 290",will it interchange?

 

[billbayliner]

Re: interchangeable upper gearcase on 275T

i need to replace the upper gearcase on my 87 capri with a 350 penta and 275t outdrive.their is an uppercase for sale on evilbay,he says its a"VOLVO PENTA UPPER UNIT FOR SP, 270, 280, 290",will it interchange?

According to my files here is what I have.

First off, I cannot find a 275T. I can find a 270T

From the 270T to the 275 the changes were: 290 upper gear head and electro mechanical tilt.

Now the 290A upper has a different double bearing box so it is not a direct swap.

 

[greeneyegi]

Re: interchangeable upper gearcase on 275T

the owner had the outdrive worked on years ago after damaging the lower ond.it now has a duoprop on it and i cant really be for sure something else wasnt replaced too.would the tag on it help identify this thing?
heres the #on the upper case 27148752b
is their any other identifing marks to check.

 

[Don S]

Re: interchangeable upper gearcase on 275T

One of the things you will need to find out is which method of attaching the helmet you have and what they other upper has.
They must be the same.

 

[greeneyegi]

Re: interchangeable upper gearcase on 275T

they both have the two bolt attachment for the helmet,i asked about the numbers on his part and this is the reply...
"the numbers on the box are 853006 PA2. there is a stamped #87 on the u joint housing. Also there is a metal tag with the following: 853575, 275A, 215,3102047225. Don't know what motor it came off of. I bought it for a AQ131D with a SP lower but never needed it due to the fact I sold the boat before I received the part. The spline is 26 teeth. Hope this helps you out. Everyone says these things are interchangeable but I'm no expert".

 

[Don S]

Re: interchangeable upper gearcase on 275T

Also there is a metal tag with the following: 853575, 275A, 215,3102047225.

It came off of a 275 drive, and the 215 indicates the drive it came off of was a 4 cylinder. Since the gear ratio changes in the lower unit, it should work fine for your drive.

One note though. you have a V8 and the upper is for a 4 and the gear backlash is slightly different.
ratio 1.61:1 .............................................. 0.15–0.25 mm (0.006–0.010")
ratios 1.89:1 and 2.15:1 ............................. 0.08–0.18 mm (0.003–0.007")
Will it make any difference ????? I don't know. Never tried it.

One thing you MUST do, is to re-shim the new upper to fit your intermediate housing.

View attachment Shimming.pdf

 

[greeneyegi]

Re: interchangeable upper gearcase on 275T

thanks for the help,now will the gears in this unit hold up behind an 8 cyl?or are they the same size?

 

[Don S]

Re: interchangeable upper gearcase on 275T

Same gears.

 

[greeneyegi]

Re: interchangeable upper gearcase on 275T

i recieved my ebay upper gear housing,everything seems good ,all the splines match up.
im measuring to shim it now and my measurements come up with .004+ the .06=.064.thats really thick.their wasnt anything near that on it before.
so im looking in their a little more,heres pics of the damage from before,could that damage be from the wrong amount of shim,after years of use?the whole shaft broke through the top,not during a shift but cruising along.

 

[greeneyegi]

Re: interchangeable upper gearcase on 275T

my bad i didnt notice its mm