Bell Housing Dial Indication Reads 0 10 22 14

The past x years has seen a significant shift in the amount of new overdrive 5 & 6-speed transmissions being retro-fitted into older cars and trucks. There is just something nostalgic about rowing gears in a archetype muscle motorcar that can't be satisfied by any other means. Pair that up with the new fuel injected engines available today and you accept a combination of modern power with classic styling that yous just tin can't replicate in a new motorcar. Just… before nosotros get as well geeked up and rush to replace that tired 3 or 4-speed, nosotros need to be sure nosotros accept the proper precautions for a trouble free installation and a good long life for your new transmission.

In the past, if you've had a car with a factory 4-speed and y'all needed to change out to another 4-speed, it was an easy swap over equally nothing really needed to be inverse. Today in many of the builds we run across a modify in flywheels, clutches, and types of bellhousings to accommodate these newer transmissions. Truthful, many of the new 5-speeds will commodities into the aforementioned bellhousings that those 4-speeds came out of, but if the bellhousing has been removed from the engine it volition be important to re-marshal the bellhousing upon installation.

Before installing your new transmission, information technology is very important to make sure that your bellhousing is properly aligned with the centerline of the crankshaft. You will also want to take the time to ensure that the flywheel is flat against the crankshaft likewise. In this guide, nosotros will embrace the processes of aligning all the components to ensure a great feel once all the new parts are installed. The concluding thing anyone wants is to spend a few thousand on a transmission bundle only to have problems a few hundred miles downward the road.

A bellhousing that is not concentric or parallel with the crankshaft centerline will requite the transmission poor shift quality as it is putting excessive side load on the input shaft. Y'all may likewise experience accelerated clutch article of clothing, date problems, accelerated input shaft bearing wear, airplane pilot bushing noise/excessive wearable, and an overall dissatisfying feel with the functioning of your new transmission. Even if you exercise a dry fit and everything "slides right together" doesn't guarantee a proper alignment. The only manner to know for sure is to take the time to practise these measurements.

Checking the bellhousing alignment tin be a tedious chore, especially if the engine is still in the car, but it is essential for proper operation. If anything, do the alignment to ensure that if you should have a warranty merits that it will not be immediately dismissed due to improper alignment. (Trust us, information technology is immediately axiomatic when a transmission wasn't aligned properly, this will almost ever void any warranty claims)

Measurement Quick Reference
Standard Automotive Bellhousing Alignment Specifications:
Concentric: +/-.005" or .010" TIR Parallel: +/-.001" or .002" TIR
Hi-Performance 7,500+ RPM Bellhousing Alignment Specifications:
Concentric: +/-.0025" or .005" TIR Parallel: +/-.0005" or .001" TIR
Flywheel runout .001" to .005" Max (less is always better)

Earlier yous get started it is always helpful to go ahead and ensure a smooth, make clean mating surface for all the components. This means metal to metal contact may be the only way to become the measurements y'all need. Normally you will be able to get by with making sure the block surface and crank flange is rust/paint complimentary and the dowel pins are clean of any droppings. At that place shouldn't exist any nicks or burrs either. In some rare cases, information technology may be necessary to clear the paint from the bellhousing if there is meaning build up. A bellhousing that is quite a bit out of parallel volition need to be shimmed regardless.

Flywheel Runout

The first part of a successful install will be to ensure that your flywheel is parallel with the crank shaft flange. This will give you a good foundation to piece of work from when checking the bong housing alignment.

• Offset be sure the crank flange is clean/rust costless. Bolt up the flywheel and torque the bolts to spec.
• Prepare up your dial indicator perpendicular to the flywheel clutch surface. This can be done past attaching the magnetic base of operations to the oil pan or engine block.
• Be sure to zero out your indicator and mark your starting point. Then slowly crank the engine by paw for 1 full revolution (360*) to be certain you come back to a zero reading at your starting bespeak. Do this one more revolution to ensure repeatability and that your dial indicator is mounted securely.
• In one case you have your starting bespeak established make another rotation and note for any depression (negative) readings. If you take any negative readings, mark that spot and that volition be your new null starting indicate. If you have no negative readings move on to the next step.
• Now that yous accept verified your zero-starting point make a couple revolutions and note any high spots. You should cease up with no more than than .005" TIR. As always, the lower number the improve.
• If you end up with more .005" TIR in that location is a possibility that your flywheel is warped, damaged, or needs to be resurfaced. At this bespeak it may as well be necessary to check the crank flange for run out also to be certain information technology does not accept whatsoever damage.
• Once you accept your flywheel runout within spec yous are ready to move onto checking the bong housing alignment.

** Annotation: If you are working with an aluminum flywheel you may need to remove it for the bellhousing alignment. This volition permit you to mount the magnetic punch indicator base to the crankshaft flange for a more solid connexion.

Checking Bellhousing Concentric Alignment

At that place are different procedures to follow depending on your transmission. The TKO 5-speed and Magnum 6-speed utilize two different styles of bellhousing. The TKO v-speed can be punch indicated on the bellhousing opening, whereas, currently, to do a proper alignment for the Magnum 6-speed, the front cover of the manual will have to be removed and bolted to the bellhousing so that the input shaft bearing race can be utilized for measuring. From there the measuring procedures are the aforementioned.
TKO 5-speed owners: In that location is i more item to be checked before you get started: the front bearing servant on the manual. It is the outer diameter of this retainer that determines the concentric placement of the manual on the bellhousing, not the manual bolts. Therefore, it is important that the begetting retainer be the right ane to piece of work with the bellhousing existence used. The retainer should exist a snug fit in to the opening in the bellhousing. If information technology is non, some other retainer of the proper diameter must exist plant (most manufacturers take produced bearing retainers in a number of different diameters). Some other alternative is to apply a spacer bushing in the bellhousing opening.

• Later ensuring you have a clean/rust free mating surface. Secure the bellhousing to the engine block and torque all bellhousing to engine bolts to specification. If using a scattershield, make certain the cake plate is installed. Magnum half-dozen-speed owners will besides bolt on your front embrace at this bespeak, but be certain to attach your magnetic dial indicator base to the flywheel before the front cover goes on.

Annotation: The stock dowel pins must protrude out by the cake plate/scattershield and locate on the cylindrical part of the dowel pins, non the tapered end. If the scattershield is resting on the tapered stop, it volition cause an inaccurate alignment reading. If necessary, tap the stock dowel pins rearward, simply enough for the tapered end to beetle through the scattershield

• With the engine cylinder #one on TDC (Acme Dead Center), install the dial indicator base of operations on the flywheel. Adjusting the plunger to contact the within border of the bellhousing transmission annals hole at 12:00, or if aligning for a Magnum 6-speed, you will apply the input shaft bearing race to measure from. If needed, removing two flywheel bolts 180* apart for the punch indicator to sit flush on the flywheel is OK.

Note: The magnetic based indicator does not demand to be on the exact heart of the flywheel. TDC/12:00 dial indicator setup will allow ameliorate communication with your helper to cease at TDC/12:00 for the repeatability checks.
Aluminum Flywheel Users: you will need to remove your flywheel for the alignment check. The magnetic base indicator will not attach to an aluminum flywheel.

• With the dial indicator on (0) zero and mounted securely at 12:00, your helper can rotate the crankshaft 360* slowly. Your job is to note the punch indicator reading, y'all are looking for the most (-) negative number on the punch indicator every bit it rotates the 360*. When your helper rotating the crankshaft stops on TDC, your punch indicator should read (0) zero at 12:00. If you read (0) nix, then y'all have verified your dial indicator is mounted securely. Do another crankshaft rotation to double check your punch indicator however reads (0) aught at 12:00.
• With the dial indicator still secured at 12:00; note the most (-) negative number of the punch indicator during your next 360* rotations. Once y'all are certain where the near (-) negative number is, mark the bellhousing. This most (-) negative number volition be your new dial indicator (0) null location.

Notation: The about (-) negative number dial indicator reading can exist at whatever location within your 360* rotation.

Bellhousing Mis-Alignment Exercise Example:

If you have determined your most (-) negative number is at viii:00; rotate the crankshaft until the dial indicator is at 8:00 and (0) zero the punch indicator. Every bit your helper rotates the crankshaft from the new 8:00 (0) zero location, your most (+) positive number should be roughly at 2:00 or 180* from the new 8:00 (0) nothing location. The TIR (Total Indicator Reading) of the dial indicator needle from 8:00 to ii:00 is your bellhousing register hole to crankshaft centerline misalignment. If the TIR was +.028" on the dial indicator, you divide .028" / two = .014". and .014" would be the needed showtime dowel pivot to right your bellhousing concentric misalignment. The .014" kickoff dowel pins would as well betoken towards 2:00 to correct the bellhousing mis-alignment.

Checking Bellhousing Parallel Alignment

• With the engine on TDC and the dial indicator base however mounted on the flywheel, adapt the plunger to contact the front face of the bellhousing at 12:00.

Note: The bellhousing front face is the contact surface area your transmission mounts to. You tin can add a slice of packaging tape to encompass the clutch fork pivotball threaded hole. The packaging tape will also permit the plunger to glide over the hole opening.

• With the dial indicator on (0) zero and mounted securely at 12:00, your helper can rotate the crankshaft 360* slowly. Every bit earlier, your job is to annotation the punch indicator reading, you are looking for the most (-) negative number on the punch indicator equally it rotates the 360*. When your helper rotating the crankshaft stops on TDC, your dial indicator should read (0) null at 12:00. If you lot read (0) zero, then you have verified your dial indicator is mounted securely. Do some other crankshaft rotation to double cheque your dial indicator still reads (0) nil at 12:00.

• Your most (-) negative number will require shims between the engine block and bellhousing to correct the parallel alignment.

Bellhousing Alignment Helpful Hints

Do the concentric bellhousing alignment check, but do not make any beginning dowel pin corrections at this time.

Do a parallel alignment check and if needed, shim the bellhousing to achieve parallel alignment specs.
Note: Adjustment a bellhousing to within parallel specs will modify the bellhousing concentric reading.

Do some other concentric alignment check and use the right offset alignment dowel pins to reach your concentric alignment specifications.

TIR = "Total Indicator Runout". The needed Offset Dowels to achieve the concentric alignment specs volition e'er exist ½ of your TIR. TIR of .028" will use a .014" offset dowel pin to right the concentric misalignment.

Total Indicator Reading	½ of TIR	Employ Offset Dowels
.012" to .020"	.006" to .010"	.007"
.022" to .034"	.011" to .017"	.014"
.036" to .052"	.018" to .026"	.021"

The ameliorate a bellhousing is indexed and dial indicated to the crankshaft, the smoother performance, higher RPM shifts, and transmission longevity you will experience.

If your bellhousing requires beginning dowel pins (contact your local speed shop and come across if the dowel pins are bachelor in the proper offset for your block). Earlier installing the offset pins we recommend to drill and tap a small hole into the side of each, dowel pin pigsty (in the block) so that a small Allen-caput set screw can be used to lock the first pins in the proper orientation after alignment is completed. When installed, the offset dowel pins can be adjusted with a screw-driver to obtain the proper alignment. In some cases, the dowel pins must be polished with a strip of emery cloth to permit them to exist rotated in the dowel pin holes with a screw-commuter. Adjustment with these offset pins can be tedious and time consuming so be patient. Later this is completed, tighten all bellhousing bolts and recheck the alignment one more time. If everything is okay, the bellhousing portion of the chore is done and y'all are ready to move forward with the balance of the installation.

There is a lot of data here to digest, only do not let it overwhelm you or make you nervous. The majority of the time your bellhousing will autumn within spec and you will exist good to become, but there are some instances where it will be necessary to apply the outset dowel pins and information technology is important to have the necessary steps to become the proper alignment. This extra time spent setting everything up properly will save you many hours and dollars later should yours be out of the adequate tolerance range. We stress the importance of this considering of the issues we've seen over the years and we want to try and save you the fourth dimension and expense of correcting this trouble at a later time when the harm has already been done.

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Source: https://www.bowlertransmissions.com/bellhousing-alignment-install-guide/

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