I would rate this installation at a 5 out of 10 for difficulty.
Tools needed:
1) 12mm 12point closed end wrench or socket with ratchet
2) 8mm hex (allen) wrench or ratchet bit with ball end 8mm hex
3) 10mm closed end wrench or socket with ratchet
4) 13mm socket with extension and ratchet
5) pry bar or large flat blade screwdriver
6) 4x ramps with built in wheel chocks (or equivilant)
7) angle finder (digital is preferred)
8) whatever tools are required to remove your exhaust (they vary with BOSS or GT stock and aftermarket exhaust systems)
STEP 1: elevate vehicle
you want to gain as much room as possible to work under the car safely. it is also important not to unload the rear suspension to accomplish this. i used a combination of 2 ramps and 2 cinder blocks. both are 7.5" high. the front should go up first, since a jack will not fit under the car up front with the rear already elevated. you can drive the front wheels up the ramps or jack it up (unloading the front suspension is not critical). set the chock to make sure the car will not roll off of your platform. now jack up the rear end from the rear axle pumkin. this prevents the rear suspension from unloading. place your platforms under the rear tires or place jack stands under each end of the axle tubes. set the rear of the car down on the platforms or jack stands. set the parking brake. if you used platforms under the rear tires, keep the jack under the pumpkin without pressure. you will need it later. your car should now look like this:
STEP 2: lower the exhaust
at a minimum, lower the front end of the exhaust and let it pivot down to gain somewhat obstructed access to the driveshaft. if you want clear access, remove the pipes between the cats and the over axle pipes. i chose to lower just the front. it was cumbersome, but worked.
STEP 3: remove the factory 2-piece driveshaft
i cant say what is the best order, but i chose to unbolt the the front, then the rear, then the center. any order you do it in, take care not to drop it when removing...there's even a sticker on the shaft that says "scrap if dropped"!
using the 12mm 12-point wrench, remove the 4 bolts securing the front of the driveshaft to the transmission flange. you will need to rotate the driveshaft 180 degrees to gain access to all the bolts. when you need to rotate, jack the pumpkin up off the platform to allow the wheels to turn. disengage the parking brake and place the transmission in neutral. rotate the driveshaft 180 degrees. reengage the parking brake and lower the pumpkin back onto the platform. mark the flange where one of the u-joint bearings sits in the yoke. for the best balance, you will want to match the position of the stock yoke with the dynotech yoke. it is a good practice to permanantly mark both the flanges and factory driveshaft, so that if you decide to return to stock someday, you can put the factory driveshaft back in the exact location.
using the 10mm wrench, remove the 6 bolts securing the rear of the driveshaft to the axle pinion flange. the driveshaft will have to be rotated the same as the front procedure to remove all 6 bolts. to save time, remove the 2 front bolts and the 3 rear bolts, then rotate the driveshaft and remove the last 2 front and 3 rear bolts.
using the 13mm socket, extension and ratchet, remove the 2 bolts securing the center bearing to the body.
using a pry bar or large flat blade screwdriver, pry the front joke from the flange and the cv from the pinion flange.
now carefully remove the driveshaft without letting the tube impact anything. with the exhaust removed, it can come straight down. with the front of the exhaust lowered, it must be lowered onto the exhaust and brought forward to be removed.
STEP 4: checking and setting angles
with a properly balanced driveshaft, vibrations come only from flange angles that are out of the tolerance of the driveshaft joints. the Dynotech driveshaft can operate with as much as 5 degrees of misalignment, but all double universal driveshafts will sacrifice longevity if the input and output are not parallel within 3 degrees. don't worry, this is not hard to accomplish.
first, you need to know what your angles are. place the angle finder on a flat surface of the transmission flange. record the angle. repeat for the axle pinion flange.
the trans should be angled down towards the rear. the pinion should be angled up towards the front or at zero. lets say the trans is at 3 degrees down and the pinion is at 3 degrees up. this makes the centerlines parallel to eachother. this is the perfect scenario for the driveshaft...except for the fact that under accelleration, the rear end twists up about 2 degrees(cw, if viewed from the driver side of the car). since the highest loads on the driveshaft are seen under accelleration, the ideal drivetrain angle places the centerlines in parallel then, not at rest. to accomplish this, we want to set our prevoiusly measured 3 degrees up on the pinion to 1 degree up. this will make our angle 3 degrees up under accelleration. for the info used above, this is what it should look like:
if you have adjustable aftermarket trailing arms in the rear, make adjustments until you get the number you need. if you have stock trailing arms with no adjustment, you need to make a judgement call on additional parts. if your angles are within 3 degrees of optimum, you will be fine. if not, you really want to consider aftermarket upper or lower arms with adjustability to get your angles within tolerance.
STEP 5: installing the Dynotech driveshaft
using the 8mm hex wrench, the 2 sheer bolts must be installed in the pinion flange with locktite and torqued to 25ft/lbs. they are to be located 180 degrees from eachother. for the easiest access, place them horizontal as shown.
compress the driveshaft before bringing it under the car. the slip joint is VERY tight and is difficult to do under the vehicle. carefully bring the driveshaft into the transmission tunnel (do not allow the tube to impact anything) and attach the billet aluminum yoke to the pinion flange wit hteh 2 blind holes engaging with the 2 previously installed sheer bolts. install the 4 bolts with the 8mm hex wrench. a ball end wrench may be required. a ball end bit with a ratchet is the best way. tighten the 4 bolts to 25ft/lbs. the driveshaft rotating procedure from STEP 3 will have to be implemented to get all 4 bolts tightened. next, bring the front of the driveshaft up to the transmission flange. the driveshaft may need to be further comressed or extended to get it to seat on the flange landing. get it to fully seat on the flange and rotate the transmission flange until the mark made in STEP 3 lines up with the u-joint bearing in the yoke (the same position as the original driveshaft). install the original 4 bolts with locktite and torque to the manufacturer's specs (i don't know what this is...i tighten until i grunt). again, the driveshaft needs to be rotated to gain access to all 4 bolts.
DOUBLE CHECK ALL 8 BOLTS ARE TORQUED PROPERLY!!
STEP 6: button it up and drop it down
reverse your exhaust disassembly procedure. before tightening everything back up, make sure your mufflers didn't shift (mine did and rattled until i figured out they shifted back and hit my trailer hitch crossbar). bring the car back down to terra firma.
STEP 7: test drive
you know the drill. do your thing. you will immediately notice less clunking and a more direct link feeling. you will also notice livlier accelleration from a stop. if you already had an adjustable upper arm, the noise level has not changed much. if you installed one with the driveshaft, you will notice gear noise. don't panic...its normal and due to the tighter bushings (or sherical bearings) in the armarm, not the driveshaft. you may experience vibrations you didn't remember before. don't worry...they were there all along. you just weren't concentrating on them before. if the driveshaft was having an issue with balance or engle misalignment, it would rattle the fillings out of your teeth.
i have one issue that drives me nuts. when coasting in a state of equilibrium (engine isn't slowing down or accellerating the car), there is a terrible rattling noise. i found out that the rear gears have way too much backlash and the driveshaft is allowed around 5-10 degrees of rotation without moving the wheels. this slop is causing my rattling. with the stock driveshaft, it had so much slop in itself, that i guess it all acted as an isolator from the gear slop? i am going to have it corrected asap. i wanted to include this info in case someone else experienced this rattling after a 1-piece install.
Tools needed:
1) 12mm 12point closed end wrench or socket with ratchet
2) 8mm hex (allen) wrench or ratchet bit with ball end 8mm hex
3) 10mm closed end wrench or socket with ratchet
4) 13mm socket with extension and ratchet
5) pry bar or large flat blade screwdriver
6) 4x ramps with built in wheel chocks (or equivilant)
7) angle finder (digital is preferred)
8) whatever tools are required to remove your exhaust (they vary with BOSS or GT stock and aftermarket exhaust systems)
STEP 1: elevate vehicle
you want to gain as much room as possible to work under the car safely. it is also important not to unload the rear suspension to accomplish this. i used a combination of 2 ramps and 2 cinder blocks. both are 7.5" high. the front should go up first, since a jack will not fit under the car up front with the rear already elevated. you can drive the front wheels up the ramps or jack it up (unloading the front suspension is not critical). set the chock to make sure the car will not roll off of your platform. now jack up the rear end from the rear axle pumkin. this prevents the rear suspension from unloading. place your platforms under the rear tires or place jack stands under each end of the axle tubes. set the rear of the car down on the platforms or jack stands. set the parking brake. if you used platforms under the rear tires, keep the jack under the pumpkin without pressure. you will need it later. your car should now look like this:
STEP 2: lower the exhaust
at a minimum, lower the front end of the exhaust and let it pivot down to gain somewhat obstructed access to the driveshaft. if you want clear access, remove the pipes between the cats and the over axle pipes. i chose to lower just the front. it was cumbersome, but worked.
STEP 3: remove the factory 2-piece driveshaft
i cant say what is the best order, but i chose to unbolt the the front, then the rear, then the center. any order you do it in, take care not to drop it when removing...there's even a sticker on the shaft that says "scrap if dropped"!
using the 12mm 12-point wrench, remove the 4 bolts securing the front of the driveshaft to the transmission flange. you will need to rotate the driveshaft 180 degrees to gain access to all the bolts. when you need to rotate, jack the pumpkin up off the platform to allow the wheels to turn. disengage the parking brake and place the transmission in neutral. rotate the driveshaft 180 degrees. reengage the parking brake and lower the pumpkin back onto the platform. mark the flange where one of the u-joint bearings sits in the yoke. for the best balance, you will want to match the position of the stock yoke with the dynotech yoke. it is a good practice to permanantly mark both the flanges and factory driveshaft, so that if you decide to return to stock someday, you can put the factory driveshaft back in the exact location.
using the 10mm wrench, remove the 6 bolts securing the rear of the driveshaft to the axle pinion flange. the driveshaft will have to be rotated the same as the front procedure to remove all 6 bolts. to save time, remove the 2 front bolts and the 3 rear bolts, then rotate the driveshaft and remove the last 2 front and 3 rear bolts.
using the 13mm socket, extension and ratchet, remove the 2 bolts securing the center bearing to the body.
using a pry bar or large flat blade screwdriver, pry the front joke from the flange and the cv from the pinion flange.
now carefully remove the driveshaft without letting the tube impact anything. with the exhaust removed, it can come straight down. with the front of the exhaust lowered, it must be lowered onto the exhaust and brought forward to be removed.
STEP 4: checking and setting angles
with a properly balanced driveshaft, vibrations come only from flange angles that are out of the tolerance of the driveshaft joints. the Dynotech driveshaft can operate with as much as 5 degrees of misalignment, but all double universal driveshafts will sacrifice longevity if the input and output are not parallel within 3 degrees. don't worry, this is not hard to accomplish.
first, you need to know what your angles are. place the angle finder on a flat surface of the transmission flange. record the angle. repeat for the axle pinion flange.
the trans should be angled down towards the rear. the pinion should be angled up towards the front or at zero. lets say the trans is at 3 degrees down and the pinion is at 3 degrees up. this makes the centerlines parallel to eachother. this is the perfect scenario for the driveshaft...except for the fact that under accelleration, the rear end twists up about 2 degrees(cw, if viewed from the driver side of the car). since the highest loads on the driveshaft are seen under accelleration, the ideal drivetrain angle places the centerlines in parallel then, not at rest. to accomplish this, we want to set our prevoiusly measured 3 degrees up on the pinion to 1 degree up. this will make our angle 3 degrees up under accelleration. for the info used above, this is what it should look like:
if you have adjustable aftermarket trailing arms in the rear, make adjustments until you get the number you need. if you have stock trailing arms with no adjustment, you need to make a judgement call on additional parts. if your angles are within 3 degrees of optimum, you will be fine. if not, you really want to consider aftermarket upper or lower arms with adjustability to get your angles within tolerance.
STEP 5: installing the Dynotech driveshaft
using the 8mm hex wrench, the 2 sheer bolts must be installed in the pinion flange with locktite and torqued to 25ft/lbs. they are to be located 180 degrees from eachother. for the easiest access, place them horizontal as shown.
compress the driveshaft before bringing it under the car. the slip joint is VERY tight and is difficult to do under the vehicle. carefully bring the driveshaft into the transmission tunnel (do not allow the tube to impact anything) and attach the billet aluminum yoke to the pinion flange wit hteh 2 blind holes engaging with the 2 previously installed sheer bolts. install the 4 bolts with the 8mm hex wrench. a ball end wrench may be required. a ball end bit with a ratchet is the best way. tighten the 4 bolts to 25ft/lbs. the driveshaft rotating procedure from STEP 3 will have to be implemented to get all 4 bolts tightened. next, bring the front of the driveshaft up to the transmission flange. the driveshaft may need to be further comressed or extended to get it to seat on the flange landing. get it to fully seat on the flange and rotate the transmission flange until the mark made in STEP 3 lines up with the u-joint bearing in the yoke (the same position as the original driveshaft). install the original 4 bolts with locktite and torque to the manufacturer's specs (i don't know what this is...i tighten until i grunt). again, the driveshaft needs to be rotated to gain access to all 4 bolts.
DOUBLE CHECK ALL 8 BOLTS ARE TORQUED PROPERLY!!
STEP 6: button it up and drop it down
reverse your exhaust disassembly procedure. before tightening everything back up, make sure your mufflers didn't shift (mine did and rattled until i figured out they shifted back and hit my trailer hitch crossbar). bring the car back down to terra firma.
STEP 7: test drive
you know the drill. do your thing. you will immediately notice less clunking and a more direct link feeling. you will also notice livlier accelleration from a stop. if you already had an adjustable upper arm, the noise level has not changed much. if you installed one with the driveshaft, you will notice gear noise. don't panic...its normal and due to the tighter bushings (or sherical bearings) in the armarm, not the driveshaft. you may experience vibrations you didn't remember before. don't worry...they were there all along. you just weren't concentrating on them before. if the driveshaft was having an issue with balance or engle misalignment, it would rattle the fillings out of your teeth.
i have one issue that drives me nuts. when coasting in a state of equilibrium (engine isn't slowing down or accellerating the car), there is a terrible rattling noise. i found out that the rear gears have way too much backlash and the driveshaft is allowed around 5-10 degrees of rotation without moving the wheels. this slop is causing my rattling. with the stock driveshaft, it had so much slop in itself, that i guess it all acted as an isolator from the gear slop? i am going to have it corrected asap. i wanted to include this info in case someone else experienced this rattling after a 1-piece install.
