lupinsea
08-07-2008, 05:06 PM
Really wordy for a simple concept but I try and explain things for the Jeep crowd. :D
Repost I made to a few Jeep boards. . . just sharing here.
Mirror Relocation Brackets - Custom Fabrication
CONTENTS
1) Vehicle Setup
2) Overview / Performance Review
3) Fabrication / Installation
4) Additional Notes
) VEHICLE SETUP
This modification can be performed on stock of altered Jeep and requires no previous modifications. Any dimensions given relate to a Jeep TJ Wrangler. Dimension and design for other eras of Jeeps should be verified.
2) OVERVIEW / PERFORMANCE REVIEW
Overview:
Jeeps are designed with easily removable doors. But in order for Jeeps to run without doors the side mirrors must either be relocated onto the body tub or additional mirrors attached to the Jeep. A secondary mirror can be bolted in to the upper (now empty) door hinge. But this takes time to bolt in and requires tools. Plus, any time the door is reinstalled the mirror must be unbolted and removed undermining the convenience of the removable doors. The alternative is to install a mirror relocation bracket, a piece of metal to permanently mount the mirror on the body. Once installed there's no need to mess with tools or disassembly and the doors can be removed and reinstalled at will.
Problems With Current Aftermarket Brackets:
Versions for earlier Jeeps (pre-03 I believe) have a simple hole in some bracket tabs through which the mirror post is inserted. The stock spring is removed from the mirror and there are no detents in the upper bracket ear. The stock detents allow the mirror to interface with the stock mount and keep the mirror at a semi-fixed position.
By spring-loading this assembly it allows the mirror to deflect and fold back when struck by enough force. But otherwise the mirror is in a fixed position
By removing this feature the relocation brackets are relying solely on the frictional clamping forced of the nut on the end of the mirror post. Over tightening can easily snap the threads off the aluminum mirror post. Additionally as the mirror is brushed against trees and is knocked back it can tighten the nut causing it to eventually overtighten and fail. And if it doesn't fail then the connection loosens and requires further tightening which can then cause it to fail.
Therefore, problems with current bracket designs include:
- no utilization of factory spring-loaded positioning detents
- reliance of frictional clamping force to fix mirror into place
- potential overtightening during mirror installation
- potential overtightening due to brushing mirror against other objects
- need for retightening as mirror is swung back and forth wearing contact surface
Aftermarket brackets for '03+ Jeeps do relocate the whole mirror assembly but they project out nearly 1.5-2" away from the Jeep. By pushing the mounting surface further out from the Jeep it simply provides a better chance that the mirror will hit something, not to mention greater leverage on the mount if the mount itself is caught.
First Remedy - Failure:
The first attempt to fix the above problems was to modify existing aftermarket relocation brackets. A piece of steel pipe was to be welded to the bottom of a relocation bracket by removing the lower ear. This would mimic the spring pocket on the stock brackets. A thicker piece of steel was welded to the top of the upper ear and detents cut into this (Fig 1). The concept was decent but due to a personal lack of fabrication skill the necessary accuracy just wasn't achieved. As a result there was unacceptable slop in the detents. Also, this design tied the bracket into one particular mirror (see Additional Notes). This solution was deemed a failure and abandoned.
http://homepage.mac.com/jgreening/.Pictures/Jeepmods/mirror%20relocation%20brackets/100_9210a%20copy.jpg
Fig 1. Failed attempt at modifying my current relocation brackets.
Tolerances and accuracy were unacceptable.
Slim Profile Mirror Bracket Concept - Success:
The Slim Profile Bracket Concept uses two plates of steel that overlap (Fig 2). One plate is the mounting surface to the Jeep, the other is for the mirror. Total thickness is only 1/2" (vs. 1.5-2" of the '03+ brackets). It allows for the entire stock mirror assembly (mirror, mount, spring, and hardware) to be moved onto the new bracket so that the stock spring loaded detent features are also retained.
http://homepage.mac.com/jgreening/.Pictures/Jeepmods/mirror%20relocation%20brackets/3D_Bracket.jpg
Fig 2. 3D exploded view of the new bracket design illustrating
the different components
The key to this is that the mounting hardware to attach the bracket to the Jeep must be accessible. The '03+ aftermarket brackets do this by greatly spacing out the mirror mounting plate. The Slim Profile bracket concept does it by drilling a large enough hole in the outer plate. The body mount fastener can then be inserted through the outer plate to reach the inner plate. This also allows the mirror to tuck closely into the body and close to the door hinge. The mirror is then installed on to the outer place.
Performance Review:
Visibility is the same as the regular aftermarket brackets so there is no improvement here but there is no loss compared to the aftermarket bracket solution either. That is to say, the driver's side mirror is visible and the passenger side mirror can be difficult to see without leaning over. The issue is the mirrors are moved forward from the original door location. On the passenger side the windshield and door frame are then in the way. There are no obstructions on the driver's side, however. Once the doors are removed, the passenger side mirror is visible.
One big improvement, however, is that now the passenger side mirror stays put because the detents can be used again. Prior to this, whenever the mirror would get hit I'd give up on it and leave it at whatever angle it was knocked to. Now it's easy to snap back into position. The same is true for the driver's side mirror.
With the complete OEM mirror (or replacement mirror) and it's base now mounted on the Slim Profile brackets the mirror does indeed stay in position. It's not loose. And there's no need to monkey with adding or remove a hinge-type mirror.
Costs:
Material costs are pretty low. Nearly everything was cut out of a roughly 6" x 12" piece of 1/8" steel scrap plate that was purchased out of the scrap bin. A 1/4" x 1/2" flat stock rod was used as a spacer at the perimeter (see fabrication below). Steel costs = $4 or less. The weld-on nuts ran $1.50. Add in the cost of a can of spray paint if you don't have some laying around and the whole project came in under $10.
Time:
This project should take a few hours. There is a bunch of careful measuring and setup for cuts that takes some time. Tools required are some welding equipment, angle grinder, and a drill and drill bits.
3) FABRICATION / INSTALLATION
Preparation & Measuring:
Gather up the necessary steel for the mounting plates. A piece of 4" x 1/8" flat stock 19" long and about 14" of 1/4" x 1/4-1/2" flat stock will be enough for the project. Acquire, also, 6 nuts for the mirror bracket hardware (3 for each side). The nuts must match the mirror mount screws so remove one if you need to get it matched at the hardware store.
Either using the dimensions below (Fig 3, 4, 5 & 6) or a cardboard template layout the shape of the base plate on the steel. Due to the variable width of cut, I'd recommend laying out each piece one at a time. Wait until the pieces are cut and cleaned up for further marking.
http://homepage.mac.com/jgreening/.Pictures/Jeepmods/mirror%20relocation%20brackets/base_plate_cuts.jpg
Fig 3. Base plate cut layout from a piece of 4" flat stock
http://homepage.mac.com/jgreening/.Pictures/Jeepmods/mirror%20relocation%20brackets/mirror_plate_cuts.jpg
Fig 4. Mirror plate cut layout. Note different driver and passenger
sides. This is due to some differences in the left and right angles for the
door mirrors.
http://homepage.mac.com/jgreening/.Pictures/Jeepmods/mirror%20relocation%20brackets/bracket_driver.jpg
Fig 5. Driver's side plate alignment and notes
http://homepage.mac.com/jgreening/.Pictures/Jeepmods/mirror%20relocation%20brackets/bracket_passenger.jpg
Fig 6. Passenger side plate alignment and notes.
Initial Cutting:
Using a plasma cutter and a 1" aluminum angle as a cutting guide, the 4 main pieces were cut out of the 1/8" flat stock (Fig 7). The plasma torch, while not necessary, does make some nice and reasonably clean cuts (Fig 8.). Some slag does need to be chipped off the backside, leaving an edge that'd easily dressed. An angle grinder may also be used to make these cuts. After the cuts are made, clean and dress the edges.
http://homepage.mac.com/jgreening/.Pictures/Jeepmods/mirror%20relocation%20brackets/100_9213%20copy.jpg
Fig 7. Setting up to cut the base plates with a plasma cutter, an
angle grinder would work as well.
http://homepage.mac.com/jgreening/.Pictures/Jeepmods/mirror%20relocation%20brackets/100_9214%20copy.jpg
Fig 8. Love the plasma cutter, though. A straight edge and the
plasma make cutting plate super easy.
Before cutting the mirror plates verify the dimensions. Due to the small variability between the different OEM mirrors, half and full size door mirrors and OEM vs aftermarket mirrors it is wise to verify what length of mirror plates will be needed. The driver's side can be shorter (4 9/16"). The passenger side, however, has some odd angles for visibility as well as constraints with the location of the factory radio antenna. Therefore, use the drawings as a reference but verify dimensions.
Marking, Drilling Plates:
Using the dimensions in Fig 3 mark off the center of the main mounting holes on the base plate. Use a center punch to mark the center to keep the drill bit from wandering and to improve accuracy. Drill 7/16" holes. Using a stepped uni-bit works great as the shoulder for the next larger size step can be used to chamfer the hole edge for straight holes. With the holes drilled, use a 3/4" countersink bit to enlarged the hole enough so that the windshield mounting screws sit flush with the surface of the base plate.
Next, trace the outline of the stock rubber mirror gasket onto the mirror plates and trace the three screw hole locations (Fig 9). Mark holes with the center punch. Next, mark where the big pass-through hole will be. See plan figures (Fig 5 & 6), the back edge of the mirror plate should be 7/16" from the back edge of the base plate to give the hinge enough room. The vertical location can be variable but safe bet is to set the top edge of the mirror plate 2 1/2" from the bottom of the base plate. Drill holes. The the three mirror screw holes should be 1/4" (verify). The big pass-through hole should be 11/16". Grind down the corners of the mirror plates to match the OEM mirror base (Fig 10). I ground off the lower edge to an angle to match but left the top edge squared off with the back of the plate for easer alignment.
http://homepage.mac.com/jgreening/.Pictures/Jeepmods/mirror%20relocation%20brackets/100_9215%20copy.jpg
Fig 9. After rough cuts, trace the rubber mount gasket and screw
holes onto mirror plate.
http://homepage.mac.com/jgreening/.Pictures/Jeepmods/mirror%20relocation%20brackets/100_9216%20copy.jpg
Fig 10. Mirror hardware, mirror plate, and base plate rough
cuts and initial drilling.
.
Repost I made to a few Jeep boards. . . just sharing here.
Mirror Relocation Brackets - Custom Fabrication
CONTENTS
1) Vehicle Setup
2) Overview / Performance Review
3) Fabrication / Installation
4) Additional Notes
) VEHICLE SETUP
This modification can be performed on stock of altered Jeep and requires no previous modifications. Any dimensions given relate to a Jeep TJ Wrangler. Dimension and design for other eras of Jeeps should be verified.
2) OVERVIEW / PERFORMANCE REVIEW
Overview:
Jeeps are designed with easily removable doors. But in order for Jeeps to run without doors the side mirrors must either be relocated onto the body tub or additional mirrors attached to the Jeep. A secondary mirror can be bolted in to the upper (now empty) door hinge. But this takes time to bolt in and requires tools. Plus, any time the door is reinstalled the mirror must be unbolted and removed undermining the convenience of the removable doors. The alternative is to install a mirror relocation bracket, a piece of metal to permanently mount the mirror on the body. Once installed there's no need to mess with tools or disassembly and the doors can be removed and reinstalled at will.
Problems With Current Aftermarket Brackets:
Versions for earlier Jeeps (pre-03 I believe) have a simple hole in some bracket tabs through which the mirror post is inserted. The stock spring is removed from the mirror and there are no detents in the upper bracket ear. The stock detents allow the mirror to interface with the stock mount and keep the mirror at a semi-fixed position.
By spring-loading this assembly it allows the mirror to deflect and fold back when struck by enough force. But otherwise the mirror is in a fixed position
By removing this feature the relocation brackets are relying solely on the frictional clamping forced of the nut on the end of the mirror post. Over tightening can easily snap the threads off the aluminum mirror post. Additionally as the mirror is brushed against trees and is knocked back it can tighten the nut causing it to eventually overtighten and fail. And if it doesn't fail then the connection loosens and requires further tightening which can then cause it to fail.
Therefore, problems with current bracket designs include:
- no utilization of factory spring-loaded positioning detents
- reliance of frictional clamping force to fix mirror into place
- potential overtightening during mirror installation
- potential overtightening due to brushing mirror against other objects
- need for retightening as mirror is swung back and forth wearing contact surface
Aftermarket brackets for '03+ Jeeps do relocate the whole mirror assembly but they project out nearly 1.5-2" away from the Jeep. By pushing the mounting surface further out from the Jeep it simply provides a better chance that the mirror will hit something, not to mention greater leverage on the mount if the mount itself is caught.
First Remedy - Failure:
The first attempt to fix the above problems was to modify existing aftermarket relocation brackets. A piece of steel pipe was to be welded to the bottom of a relocation bracket by removing the lower ear. This would mimic the spring pocket on the stock brackets. A thicker piece of steel was welded to the top of the upper ear and detents cut into this (Fig 1). The concept was decent but due to a personal lack of fabrication skill the necessary accuracy just wasn't achieved. As a result there was unacceptable slop in the detents. Also, this design tied the bracket into one particular mirror (see Additional Notes). This solution was deemed a failure and abandoned.
http://homepage.mac.com/jgreening/.Pictures/Jeepmods/mirror%20relocation%20brackets/100_9210a%20copy.jpg
Fig 1. Failed attempt at modifying my current relocation brackets.
Tolerances and accuracy were unacceptable.
Slim Profile Mirror Bracket Concept - Success:
The Slim Profile Bracket Concept uses two plates of steel that overlap (Fig 2). One plate is the mounting surface to the Jeep, the other is for the mirror. Total thickness is only 1/2" (vs. 1.5-2" of the '03+ brackets). It allows for the entire stock mirror assembly (mirror, mount, spring, and hardware) to be moved onto the new bracket so that the stock spring loaded detent features are also retained.
http://homepage.mac.com/jgreening/.Pictures/Jeepmods/mirror%20relocation%20brackets/3D_Bracket.jpg
Fig 2. 3D exploded view of the new bracket design illustrating
the different components
The key to this is that the mounting hardware to attach the bracket to the Jeep must be accessible. The '03+ aftermarket brackets do this by greatly spacing out the mirror mounting plate. The Slim Profile bracket concept does it by drilling a large enough hole in the outer plate. The body mount fastener can then be inserted through the outer plate to reach the inner plate. This also allows the mirror to tuck closely into the body and close to the door hinge. The mirror is then installed on to the outer place.
Performance Review:
Visibility is the same as the regular aftermarket brackets so there is no improvement here but there is no loss compared to the aftermarket bracket solution either. That is to say, the driver's side mirror is visible and the passenger side mirror can be difficult to see without leaning over. The issue is the mirrors are moved forward from the original door location. On the passenger side the windshield and door frame are then in the way. There are no obstructions on the driver's side, however. Once the doors are removed, the passenger side mirror is visible.
One big improvement, however, is that now the passenger side mirror stays put because the detents can be used again. Prior to this, whenever the mirror would get hit I'd give up on it and leave it at whatever angle it was knocked to. Now it's easy to snap back into position. The same is true for the driver's side mirror.
With the complete OEM mirror (or replacement mirror) and it's base now mounted on the Slim Profile brackets the mirror does indeed stay in position. It's not loose. And there's no need to monkey with adding or remove a hinge-type mirror.
Costs:
Material costs are pretty low. Nearly everything was cut out of a roughly 6" x 12" piece of 1/8" steel scrap plate that was purchased out of the scrap bin. A 1/4" x 1/2" flat stock rod was used as a spacer at the perimeter (see fabrication below). Steel costs = $4 or less. The weld-on nuts ran $1.50. Add in the cost of a can of spray paint if you don't have some laying around and the whole project came in under $10.
Time:
This project should take a few hours. There is a bunch of careful measuring and setup for cuts that takes some time. Tools required are some welding equipment, angle grinder, and a drill and drill bits.
3) FABRICATION / INSTALLATION
Preparation & Measuring:
Gather up the necessary steel for the mounting plates. A piece of 4" x 1/8" flat stock 19" long and about 14" of 1/4" x 1/4-1/2" flat stock will be enough for the project. Acquire, also, 6 nuts for the mirror bracket hardware (3 for each side). The nuts must match the mirror mount screws so remove one if you need to get it matched at the hardware store.
Either using the dimensions below (Fig 3, 4, 5 & 6) or a cardboard template layout the shape of the base plate on the steel. Due to the variable width of cut, I'd recommend laying out each piece one at a time. Wait until the pieces are cut and cleaned up for further marking.
http://homepage.mac.com/jgreening/.Pictures/Jeepmods/mirror%20relocation%20brackets/base_plate_cuts.jpg
Fig 3. Base plate cut layout from a piece of 4" flat stock
http://homepage.mac.com/jgreening/.Pictures/Jeepmods/mirror%20relocation%20brackets/mirror_plate_cuts.jpg
Fig 4. Mirror plate cut layout. Note different driver and passenger
sides. This is due to some differences in the left and right angles for the
door mirrors.
http://homepage.mac.com/jgreening/.Pictures/Jeepmods/mirror%20relocation%20brackets/bracket_driver.jpg
Fig 5. Driver's side plate alignment and notes
http://homepage.mac.com/jgreening/.Pictures/Jeepmods/mirror%20relocation%20brackets/bracket_passenger.jpg
Fig 6. Passenger side plate alignment and notes.
Initial Cutting:
Using a plasma cutter and a 1" aluminum angle as a cutting guide, the 4 main pieces were cut out of the 1/8" flat stock (Fig 7). The plasma torch, while not necessary, does make some nice and reasonably clean cuts (Fig 8.). Some slag does need to be chipped off the backside, leaving an edge that'd easily dressed. An angle grinder may also be used to make these cuts. After the cuts are made, clean and dress the edges.
http://homepage.mac.com/jgreening/.Pictures/Jeepmods/mirror%20relocation%20brackets/100_9213%20copy.jpg
Fig 7. Setting up to cut the base plates with a plasma cutter, an
angle grinder would work as well.
http://homepage.mac.com/jgreening/.Pictures/Jeepmods/mirror%20relocation%20brackets/100_9214%20copy.jpg
Fig 8. Love the plasma cutter, though. A straight edge and the
plasma make cutting plate super easy.
Before cutting the mirror plates verify the dimensions. Due to the small variability between the different OEM mirrors, half and full size door mirrors and OEM vs aftermarket mirrors it is wise to verify what length of mirror plates will be needed. The driver's side can be shorter (4 9/16"). The passenger side, however, has some odd angles for visibility as well as constraints with the location of the factory radio antenna. Therefore, use the drawings as a reference but verify dimensions.
Marking, Drilling Plates:
Using the dimensions in Fig 3 mark off the center of the main mounting holes on the base plate. Use a center punch to mark the center to keep the drill bit from wandering and to improve accuracy. Drill 7/16" holes. Using a stepped uni-bit works great as the shoulder for the next larger size step can be used to chamfer the hole edge for straight holes. With the holes drilled, use a 3/4" countersink bit to enlarged the hole enough so that the windshield mounting screws sit flush with the surface of the base plate.
Next, trace the outline of the stock rubber mirror gasket onto the mirror plates and trace the three screw hole locations (Fig 9). Mark holes with the center punch. Next, mark where the big pass-through hole will be. See plan figures (Fig 5 & 6), the back edge of the mirror plate should be 7/16" from the back edge of the base plate to give the hinge enough room. The vertical location can be variable but safe bet is to set the top edge of the mirror plate 2 1/2" from the bottom of the base plate. Drill holes. The the three mirror screw holes should be 1/4" (verify). The big pass-through hole should be 11/16". Grind down the corners of the mirror plates to match the OEM mirror base (Fig 10). I ground off the lower edge to an angle to match but left the top edge squared off with the back of the plate for easer alignment.
http://homepage.mac.com/jgreening/.Pictures/Jeepmods/mirror%20relocation%20brackets/100_9215%20copy.jpg
Fig 9. After rough cuts, trace the rubber mount gasket and screw
holes onto mirror plate.
http://homepage.mac.com/jgreening/.Pictures/Jeepmods/mirror%20relocation%20brackets/100_9216%20copy.jpg
Fig 10. Mirror hardware, mirror plate, and base plate rough
cuts and initial drilling.
.