TRS Drive alignment & gimbal question
#1
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TRS Drive alignment & gimbal question
Hello,
Working on redoing my 80 Scarab S Type and am about ready to remount gimbals and mock up for new motor mounts. Question is when doing the drive alignment with the rod and disc for the TRS with BW trannys I assume that the bellhousing (helmet) is at the far lowest position of travel when positioning the disc?
Also if anyone knows what is the proper amount of clearance between the top of the gimbal ring and the transom assembly. I replaced all the bearings and seals in the transom assembly and drew up the upper pin nut tight. Now the bottom of the gimbal ring is touching the upper ear that holds the lower swivel pin. I assume that there should be some clearance here? The ring pivots nicely, should it be left high to drop as it wears, or if not i would have to loosen the upper pin nut and steering arm to allow it to drop a little?
Sorry for the long post, just want to make sure this is right before it goes back on the boat
Thanks
Brad
Working on redoing my 80 Scarab S Type and am about ready to remount gimbals and mock up for new motor mounts. Question is when doing the drive alignment with the rod and disc for the TRS with BW trannys I assume that the bellhousing (helmet) is at the far lowest position of travel when positioning the disc?
Also if anyone knows what is the proper amount of clearance between the top of the gimbal ring and the transom assembly. I replaced all the bearings and seals in the transom assembly and drew up the upper pin nut tight. Now the bottom of the gimbal ring is touching the upper ear that holds the lower swivel pin. I assume that there should be some clearance here? The ring pivots nicely, should it be left high to drop as it wears, or if not i would have to loosen the upper pin nut and steering arm to allow it to drop a little?
Sorry for the long post, just want to make sure this is right before it goes back on the boat
Thanks
Brad
#2
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Trs Alignment, Someone must know
Anybody know? I am working on this right now and I would like to be able to get my mounts drilled today. With the tailstock TRS mount can you add washers under the tailstock ears to bring the alignment more into place or is it all done with the positioning of the front mounts?
Seems like when I raise the front of the motor up to get the alignment tool fitting well the tail stock of the tranny is very close to the bottom of the hole in the transom assembly. If I add washers to the tail stock mount it helps bring the tailstock more in center of the transom assembly.
With regard to left right positioning on a trs I assume it is not that critical as there is no gimbal bearing fixed in the transom assembly as on an alpha or bravo. I just centered the helmet as best I could and will adjust the motor from there to achieve alignment, sound right?
Any help would be greatly appreciated
Thanks
Brad
Seems like when I raise the front of the motor up to get the alignment tool fitting well the tail stock of the tranny is very close to the bottom of the hole in the transom assembly. If I add washers to the tail stock mount it helps bring the tailstock more in center of the transom assembly.
With regard to left right positioning on a trs I assume it is not that critical as there is no gimbal bearing fixed in the transom assembly as on an alpha or bravo. I just centered the helmet as best I could and will adjust the motor from there to achieve alignment, sound right?
Any help would be greatly appreciated
Thanks
Brad
#3
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I'm no pro, but I believe that you should NOT change the shimming between the transom pad and the trans mounts in the back. All the adjustments should be made by moving the front of the motor up aad down. Being a complete re-fit, you may have more of a challenge. All I 've ever done is pull power to rebuild. Sounds like you have good common sense, and will do well. As long as you have the correct washers in place on the rear, the rest should be handled by moving the engine on its mounting plates. I did have one engine that didn't line up well in the back, and found I had damaged motor mounts. Good luck with your install, Nick
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What good is it to align the drive when it moves up and down. anyway. The shaft is never in the same place unless all the way down all the time. Just trying to figure out why it is so important. I would think left and right would be alot more important because that would add another angle to the yoke.
Thanks
Thanks
#5
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Btharbold,
The spacing for the ring to housing is .005-.007.
The tailststock had a spring washer and an outer fiber washer. Do not shim the tailstock use the intended washers. Intall the rear bolts and tighten down that will position the motor left and right. Adjust the motor up or down so the disc will lay flat and spin freely when perfect. Most often people settle for rear close. Take the time to get it right.
The bellhousing will adjust to a near level position. Not all the way in. When you slide the disc in place it should slide even against bellhousing . It is perfect when the disc is flat against the bellhousing completely around all 360 degrees.
If the motor is not align properly the trannie output bearing and the drive input bearings get side loaded and are likely to fail. Since you are aligning bellhousing to trannie if the bellousing is too high or has settled it will be difficult or impossible to align.
The spacing for the ring to housing is .005-.007.
The tailststock had a spring washer and an outer fiber washer. Do not shim the tailstock use the intended washers. Intall the rear bolts and tighten down that will position the motor left and right. Adjust the motor up or down so the disc will lay flat and spin freely when perfect. Most often people settle for rear close. Take the time to get it right.
The bellhousing will adjust to a near level position. Not all the way in. When you slide the disc in place it should slide even against bellhousing . It is perfect when the disc is flat against the bellhousing completely around all 360 degrees.
If the motor is not align properly the trannie output bearing and the drive input bearings get side loaded and are likely to fail. Since you are aligning bellhousing to trannie if the bellousing is too high or has settled it will be difficult or impossible to align.
Last edited by MOBILEMERCMAN; 07-13-2008 at 09:02 PM.
#6
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Thread Starter
Thanks Jim,
Turns out that the reason my tailstocks were to low is that I was not using the thackery spring in between the tailstock bushing and the transom plate. Once I put that in there it put the tailstock in a much better position to align things. The Merc schematic is a little confusing on that one.
I played with each one for a long time, and I got them pretty good I think. Disc was lying flat, dont know that I would say it will spin freely though. I was doing the mock up with a plastic mock up bbc and the BW tranny. I will check the alignment one more time when the real motors go in.
Seems like I have some difference between the two motors in their heights, probably due to a difference in where the transom assemblies were drilled orignially, Have you ever encountered this? I am just going to align each side the best I can and not worry about it.
Thanks again,
Brad
Turns out that the reason my tailstocks were to low is that I was not using the thackery spring in between the tailstock bushing and the transom plate. Once I put that in there it put the tailstock in a much better position to align things. The Merc schematic is a little confusing on that one.
I played with each one for a long time, and I got them pretty good I think. Disc was lying flat, dont know that I would say it will spin freely though. I was doing the mock up with a plastic mock up bbc and the BW tranny. I will check the alignment one more time when the real motors go in.
Seems like I have some difference between the two motors in their heights, probably due to a difference in where the transom assemblies were drilled orignially, Have you ever encountered this? I am just going to align each side the best I can and not worry about it.
Thanks again,
Brad
#7
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All you can do is align it to the transom assy. It is nice if the height s are even. Make sure everything is right and tight on transom. Get the gimble ring clearances even. A little difference in the back is multiplied many times as you move forward.
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I am also wondering about this alignment procedure specifically the part about which washers go where when bolting the tail stock to the gimbal. Does anybody have a better picture then this one? http://www.mercruiserparts.com/Show_...SSION+ASSEMBLY
Maybe someone has a manual they could scan?
Thanks
Maybe someone has a manual they could scan?
Thanks
#9
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Location: Sandown, NH - Sebago Lake Region, ME
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I am also wondering about this alignment procedure specifically the part about which washers go where when bolting the tail stock to the gimbal. Does anybody have a better picture then this one? http://www.mercruiserparts.com/Show_...SSION+ASSEMBLY
Maybe someone has a manual they could scan?
Thanks
Maybe someone has a manual they could scan?
Thanks
Anybody???