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Swapping Volvo Penta 270 to a 270T (hydraulic trim)?

69 Supersport

New member
I decided to add hydraulic trim from a B30 6 cyl to my Chevy V8 and ran it 2 problems:

1. The bolt patterns for mounting the transom shields are about 1 inch apart and therefore are not easily interchangeable.

2. The 270T 6 cyl primary drive shaft end is about 1 inch further aft then the v8.

Anyone familiar with these unforeseen differences?

I was assured by 3 independent local Volvo marine mechanics that "most Volvo Penta parts are interchangeable..." but apparently this is not the case. :(

Jim
Seattle
 
Steer clear of the "T" drive! You DO NOT want a "T" drive!

Instead, find yourself a 290, or better yet a "C" or later AQ series drive!

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I've been doing AQ series engine/drive repair for over 20 years........ probably 23 or more.

Parts availability (as in very limited), and in particular some of the rubber components, would be good reason for NOT using a T drive.

Keep in mind how short the "T" drive life span was! (it was in service for only a few short years)

You'll just have to trust me on this one!

*********
by the way:

The next power trim drive was the 280PT, but it too lived a short life span.
Parts would be difficult to source today. I'd steer clear of this one also.

Next was the 290.
It maintained a form of the Reverse Latch unit, and required the anchorage bracket for cylinder attachment.
The anchorage bracket, Rev Latch and cylinder attachment does make for some noticeable slop/play.

The "C" drive eliminates the Reverse Latch, and the cylinders now attach directly to the main suspension fork.
(this is the "good stuff" while staying within the AQ series)

All AQ series lower units can be interchangeable....
NOT so with transmissions.


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Hi RicardoMarine,

It appears much of your concern is around parts availability which I understand due to the rarity of the 270T. I talked with a guy that worked with Volvo marine in the 1970s and he said the reason they discontinued the 270T was because the trim cylinder was constantly submerged and after a few years the aluminum housing would be susceptible to corrosion issues. Since my boat is trailered and only in fresh water, I was not concerned about this and rebuilding this cylinder is quite easy with just 4 bolts to remove it. All the rubber gaskets are readily available. So are the bellows and "s" hose and other components. I also happen to have a complete working spare unit just in case.

The 270T unit I have functions very well and the design is certainly less complex than the non-trim electro-mechanical screw drive setup. When the 270T is in the down position, the pump directs pressure to the trim cylinder and when the trim cylinder is fully extended an overflow valve simply redirects the pressure to the lift cylinder. It all works like a charm and in my experience the "slop/play" you mention is non-existent in sea trials even above 50 MPH ripping through my own wake. The only issue I have with the unit is the primary drive shaft appeared to be about 5/8" too far forward as compared to other units and this meant the spline connection didn't have enough overlap. I corrected this but to date no one has been able to confirm why this was the case. No one on the entire planet seems to know much about these units at all.

I do have a question for you: I occasionally see Penta transom shields for sale that specify 4 cylinder... are all the transom shields the same regardless of the engine they are connected to?

Thanks again for your response!
Jim
 
I do have a question for you: I occasionally see Penta transom shields for sale that specify 4 cylinder... are all the transom shields the same regardless of the engine they are connected to?

The early V-8 Y-pipes and transom shields were single exhaust relief, as were the in line engines.
In the late 70's, VP introduced the double exhaust relief Y-pipe (GM V-8's) of which requires a double relief transom shield.

The two will not work together.


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I have the thru-transom exhaust on this boat. Any other differences you can think of? When I compare a 6 cylinder (B30) PDS housing to the Chevy V8 its a bit longer from the 0 Ring surface to the end of the snout (and the end of the shaft itself) which reduced the spline overlap when moving to the V8. Have you ever seen this before?
Thanks Rick
Jim
 
Ricardo is very knowledgeable regarding these outdrives. He helped me find my way thru the maze that the 270T outdrive represents. Ricardo after following the posts, perhaps a word of caution regarding gear ratios might be in order
 
http://i304.photobucket.com/albums/nn171/36TFisher/360069_2_zps315f7914.jpg

http://s304.photobucket.com/user/36TFisher/media/bh1_zps62634a1b.jpg.html?sort=3&o=51


Hi Mujibar,

I am sure I have the right gear ratios for a V8 (1.61 I believe) as I have had his boat up to 52 MPH before and the trim works like a charm. All I am trying to find is someone with experience connecting a 270T to a Chevy V8 to resolve the spline shaft overlap and bellows issue. I know this has been resolved as I saw a Donzi with a 270T and Chevy V8.
 
I don't mess with the T drives, so my knowledge is somewhat limited.

Apparently the "flywheel cover" (bell housing in the auto world), is unique to the T drive!
You may have difficulty finding one for the GM V8.


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Thanks for the response Ricardo! Its been a challenge but I am committed as its already mounted on the boat. I have recently come across some contacts at offshoreonly.com running twin 270Ts with 350s, stroked 383s and even a SBC 400 with some massive HP and they are reporting good performance and reliability so I hope to get the necessary bell housing details soon and get back on the water.

Wish me luck!
Jim
 
If you run high hp and torque, I'd recommend that you replace the main drive gear bearings in the transmission!
These will be a 30207 and 31307.
If you were to lose the 31307, you will end up with some serious gear damage!

The two driven gear bearings seem to fair very well.

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Jim, if by chance you remove the main drive gear bearing box (for seal replacement, for example), I'd at least press the "drive" gear out, and take a good look at the 31307 outer race!
It will give you a good "tell-tale-sign" of the bearing's condition.

With this transmission, it will not involve re-shimming or resetting the rolling torque value....... but you may want to tighten it up a tad!
(shim control is within the seal surface washer)
You could remove .001" to .0015" of the shim pack, and bring the rolling torque value up a bit!
But again, only if the two bearings are in great condition!!!!!

Your call!



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Dear RicardoMarine!

I have a Draco 2000 GT DC boat with Volvo Penta AQ 170A, B30 engine (6cyl, 3000ccm, 170hp) and AQ 270T outboard drive.
I have some problems with the hydraulic system. My main issue is that the drive tends to float up during dethrottling.
Could you help me, where can I buy a repair kit?
Any idea is welcome.
Thank you in advance.
Have a nice day!
 
This thread was started back in December of 2013. It is well over 4 years old now.
It would be best to start a new thread re; your specific topic.



Dear RicardoMarine!

I have a Draco 2000 GT DC boat with Volvo Penta AQ 170A, B30 engine (6cyl, 3000ccm, 170hp) and AQ 270T outboard drive.
I have some problems with the hydraulic system. My main issue is that the drive tends to float up during dethrottling.
Could you help me, where can I buy a repair kit?
Any idea is welcome.
Thank you in advance.
Have a nice day!

Since we're here......... please re-read posts #2 and #4.

I would not suggest that anyone spend a dime on a T drive.
I would suggest that you take your good hard-earned-money and spend it on a Volvo Penta 280 or later system.


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Dear RicardoMarine!

Thank you for your help.
What do you think which is the best choice AQ280 or AQ290 drive for my AQ 170A, B30 engine (6cyl, 3000ccm, 170hp, gasoline)?
Is it possibble to use the parts of the AQ270T drive as a "donor" for an other AQ280, AQ290 drive? Because my AQ270T drive was rebuilt 1 year ago so it is in a very good condition (except for the hydraulic system).
Thank you in advance.
Best wishes,
John S.
 
.........................................
Dear RicardoMarine!

Thank you for your help.
You are welcome!

What do you think which is the best choice AQ280 or AQ290 drive for my AQ 170A, B30 engine (6cyl, 3000ccm, 170hp, gasoline)?
Either will work.
The 280 std drive is not PT. The 290 is PT.
Either incorporates a reverse latch unit.


Is it possibble to use the parts of the AQ270T drive as a "donor" for an other AQ280, AQ290 drive?
I believe that the transmission and the lower gear unit would interchange. To the best of my knowledge, no other parts would interchange.


Thank you in advance.
Best wishes,
John S.
 
280/290 drives arguably the best drives Volvo made. IMHO, hydrualic trim, on a properly designed hull, is a solution in search of a problem... unless you habitually beach your boat, and then you run the risk of damaging the raw water impeller.
 
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The best drives in the AQ series family would be the SP-C, Sp-C1 and the DP-C, DP-C1 etc.
These were produced right alongside of the gimbal suspension drives (i.e., SX and DP-S) through 1996 .


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Dear RicardoMarine!
Dear Sandkicker!

What do you think, is the AQ280 drive manoeuverable forward within “Beach” (15°) while underway at low speed and idling?
I think underway at low speed and idling there are no huge forces involved. But the reverse is not possible because the reverse latch does not work and the drive goes out from the water.
Thank you in advance.
Best wishes,
John S.
 
This thread was started back in December of 2013. It is well over 4 years old now.
It would be best to start a new thread re; your specific topic.



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