Dustin Atwood
Registered Member
I am putting in a doubler set up in my 69 and was wondering if someone could posy up some pics of theirs mounted in place? What additional bracing did you use? Thank you in advance!
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NP 205/203 Doubler
- Thread starter Dustin Atwood
- Start date
Dustin Atwood
Registered Member
It may have lost a lot of pics because of the Photobucket fiasco but try this for ideas - https://ck5.com/forums/threads/the-mother-of-all-doubler-crossmember-pics-thread.233677/
Dustin Atwood
Registered Member
This is awesome thank you
The big idea to keep in mind is to hold it in there but don't over constrain it. Remember that your frame is going to flex a little and your motor mounts are going to flex a little and if the T case is mounted super solid you'll break the trans or adapter. Mounting about as solid as your engine is a decent rule of thumb.
@Stephen - What is your opinion of some of the various rear tcase mounts (with respect to a Doubler set up). I purchased one from a company that clamps around a special rear output seal retainer so it would support weight (via a leaf bushing at the crossmember) yet *might* allow for some rotational movement. My plan was to use the factory adapter bushings + similar bushings on your ORD adapter + the rear support (in conjunction with ORD motor mounts, everything poly), yay or nay?
Can of worms?
Can of worms?
bp71k5
3/4 ton status
Here's a not great view of my previous doubler setup in my 71. Just used the stock crossmember with bushing under the adaptor.
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I like my newer setup better:
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I like my newer setup better:
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Learning: On the newer set up, doesn't that mounting tab need to be sandwiched between the donut bushings?
bp71k5
3/4 ton status
I sandwiched the two shorter tabs between the bushings. May not be easy to see well in that picture.
Ok, gotcha. 
Alot of local guys have broken trans cases with their doubler kits by mounting the doubler solid to a cradle and poly mounting the cradle to the frame at four points.
I kept mine in a similar design to the oem mounting where it's in a triangle from the motor mounts to the trans mounts. I used two oem crossmembers and oem style poly mounts with diy4x motor mounts. It seems to be doing well with several seasons on this setup.
I kept mine in a similar design to the oem mounting where it's in a triangle from the motor mounts to the trans mounts. I used two oem crossmembers and oem style poly mounts with diy4x motor mounts. It seems to be doing well with several seasons on this setup.
like @Stephen and @obijuank5, have just said, a good rule of thumb is to make sure all your drivetrain mounts are like-kind. Meaning if you are going to run poly mounts for the trans/t-case supports, make sure you install poly mounts for the motor mounts too. That way, as Stephen explained, once the frame starts to flex a bit under articulation, the whole drivetrain from motor to t-case will have the same resistance from the mounts. If you have crap stock rubber mounts on the motor and nice poly mounts on the trans/t-case, there will be more movement up front by the motor with the crap mounts than the good poly mounts and usually the weak link is the trans tail housing or t-case adapter in the middle.
There always seems to be debate from the internet peoples as to which additional support on the 205 in a doubler setup is the best...honestly I think just about all of them are fine, once again as long as all your mount styles are the same (aka, poly mounts), but that's just my opinion. I have my standard t-case adapter mount but it's a poly version, and my motor mounts are DIY4x comp poly mounts, and I added a pto mount on the side of my Titan Box/205, again with a poly mount. Only had it out once, but didn't destroy anything (yet), but my brother has a similar setup on his doubler (383/700r4/203/205/Rockwells/47" LTB's) and been running it for years with no problems
There always seems to be debate from the internet peoples as to which additional support on the 205 in a doubler setup is the best...honestly I think just about all of them are fine, once again as long as all your mount styles are the same (aka, poly mounts), but that's just my opinion. I have my standard t-case adapter mount but it's a poly version, and my motor mounts are DIY4x comp poly mounts, and I added a pto mount on the side of my Titan Box/205, again with a poly mount. Only had it out once, but didn't destroy anything (yet
), but my brother has a similar setup on his doubler (383/700r4/203/205/Rockwells/47" LTB's) and been running it for years with no problems
454Sub
5/8 ton status
I did mine like this.
I just used poly square body front front eye bushings and set them up the exact same way the motor mounts are setup.
All being poly I assume this will work. They all are on the same plane so should all flex the same ish. Hopefully.
If 6 poly bushings and bolts don't hold it in I dunno what else to do.
I wish I wasn't so lazy to shape this bracket to look cleaner. But it is what it is.
I just used poly square body front front eye bushings and set them up the exact same way the motor mounts are setup.
All being poly I assume this will work. They all are on the same plane so should all flex the same ish. Hopefully.
If 6 poly bushings and bolts don't hold it in I dunno what else to do.
I wish I wasn't so lazy to shape this bracket to look cleaner. But it is what it is.
That's a neat twist on using the spring eye bushings.
We've become less enthusiastic about multiple crossmembers especially as they get farther apart. Bend one and break the drivetrain. If you mount it from one crossmember you can bend it and likely get away with it. In general we like it all mounted off our doubler adapter or magnum adapter which is why we put mounting points there. Tying into the sides and back seems to make them too stiff more often than not.
@454Sub you need to look at rotating that 205 down about 4", there's no reason to have it that high when your crossmembers are 2" below the frame and you're going to have a really hard time getting a practical driveshaft to work as it sits. We quit praying to the gods of belly clearance a while ago. It's nice when it's slick and it's nice when it's tucked up but you'll hit the bottoms of the frame rails way more than the belly section. You can drop the T-case down a LOT and taper the ends of the crossmember up to the frame so they're not below it and it'll all work a lot better.
@454Sub you need to look at rotating that 205 down about 4", there's no reason to have it that high when your crossmembers are 2" below the frame and you're going to have a really hard time getting a practical driveshaft to work as it sits. We quit praying to the gods of belly clearance a while ago. It's nice when it's slick and it's nice when it's tucked up but you'll hit the bottoms of the frame rails way more than the belly section. You can drop the T-case down a LOT and taper the ends of the crossmember up to the frame so they're not below it and it'll all work a lot better.
I will agree with this. I have my 205 pretty much in the stock location (clocking wise), and I just built a beef skid plate/bucket for the 205 that is made out of 1/4" plate. Sure mine hangs down a bit as compared to some that clock them really flat, and sure I've hit it a few times, but not nearly that often enough to justify all the work that goes into clocking it up (floor mods and/or body lifts, driveshaft angles, exhaust clearances/routing, etc...), but the fact that I've had it like that while running 42"+ tires also helps too.
The other thing I think about when clocking that high is it's gotta be hard to get enough fluid in the case to keep the gears lubricated. I know my brother clocked his 205 up pretty high (not as high as above) and he had trouble getting enough fluid in the case, so much so that he had to drill and tap a new whole in the case as a new "fill" point for fluid...something I actually didn't think about until I watched him do his setup. I guess just good things to consider with all of this...it usually isn't just bolt in and go with doubler setups
@Stephen so you're saying you recommend just using the Doubler foot and leave the OE adapter empty? A jazzy crossmember is on my to do list but not super high priority, I'm just running OE bushings on the OE adapter. If the set up only really needs one mount (yours) that really makes things easier for me and everyone else.
454Sub
5/8 ton status
I already had drilled new hole for the fill and the existing drain works. I just filled it with the normal recommended amount of fluid. And it seems to me clocked flat both shafts are partially submerged in Lucas, vs the stock clocking only the front output being submerged. Making rotation of the gears as the only way to lube the input and output bearings.
I can't easily change my clocking. Me and a friend machined this ourselves after advice from a super cool office lady at your shop. I have a long drivetrain compared to most. With my front axle moved forward an inch like it is plus being high pinion I can probably get away with two 1350 joints anyways. I'm not even close to maxing out the 1350 CV yet, and am planning on 1410s down the road anyways.
I like it totally flat. It's probably much harder to do with a GM 60 than it is mine. It's more work to package, but in reality the clocking hasn't hurt me, it's been the output on the opposite side. Traction bar, fuel lines and all that all need to be on that particular side, throw exhaust into the mix and not good.
I can't easily change my clocking. Me and a friend machined this ourselves after advice from a super cool office lady at your shop. I have a long drivetrain compared to most. With my front axle moved forward an inch like it is plus being high pinion I can probably get away with two 1350 joints anyways. I'm not even close to maxing out the 1350 CV yet, and am planning on 1410s down the road anyways.
I like it totally flat. It's probably much harder to do with a GM 60 than it is mine. It's more work to package, but in reality the clocking hasn't hurt me, it's been the output on the opposite side. Traction bar, fuel lines and all that all need to be on that particular side, throw exhaust into the mix and not good.
bp71k5
3/4 ton status
That's how I had mine for one blazer bash. No issues. I did add a second crossmember later, but it was more for looks and to make it easier to add a skid plate. But got rid of both now and went back to single mount.
