Tranny Overhaul & JDM ITR Final Drive/LSD Install

Tool List:
1.) Helm 1994, 1995, 1996, or 1998 Integra Service Manual
2.) Socket set
3.) 1/2" drive Ratchet [Pic]
4.) Pneumatic or Electric Impact Gun [Pic]
5.) 32mm 1/2" drive Socket
6.) Snap Ring Pliers [Pic]
7.) 6" or larger Bench Clamp [Pic]
8.) (2) 2'x4' pieces of wood [approx. 1ft in length]
9.) (2) 2'x4' pieces of plywood [approx. 4" to 6" in length]
10.) Feeler Gauges (.0015" minimum thickness) [Pic]
11.) Razor blade
12.) Hondabond or Permatex Ultra Grey [Pic] - I prefer's not as gooey
13.) Pry bar
14.) 2lb Sledgehammer [Pic]
15.) 8mm Rolled Punch Pin [Pic 1] [Pic 2] - Sears ($19.99)
16.) Seal Driver Set [optional] - you can use sockets and extensions instead to drive new seals/bearings in or drive stuff out [Pic]
17.) Bushing Driver Set [optional] [Pic]
18.) 9" 3/8" drive Extension
19.) 3lb Slide Hammer (5/8"x18) [optional]
20.) 5/8"x18 (F) to 3/8"x16 (M) Slide Hammer Adapter [optional]
21.) Adjustable Bearing Puller [optional] [Pic 1] [Pic 2]- Baranco Acura ($77.xx)
22.) 1 5/8" Socket
23.) 27mm 1/2" drive Deep Socket [Pic]
24.) 1/2" to 4 5/8" Bearing Splitter & 7 ton Adj 2-Jaw Puller [Pic] - splitter from ($51.95) & puller from Sears ($29.99)
25.) 14mm Box Wrench [Pic]
26.) 6" length of 1.5" PVC Pipe - [Pic] - Bloomington Hardware ($.50/ft)
27.) Brake Parts Cleaner [Pic] - Walmart ($1.69)
28.) Wash Bucket, Spic n Span/Dawn Dish Soap, Rag
29.) Whipped Cream Bucket - for holding MTF to dip parts into before assembly [Pic]
30.) Dead Blow Hammer [Pic]

Part numbers for or everything that comes with the JDM ITR Final Drive kit (courtesy of
41233-P80-E30 : 4.785 DIFERENTIAL RING GEAR
23914-P80-E30 : COLLAR RING
23221-P80-E30 : 4.785 COUNTERSHAFT

Parts numbers for Differential:
41200-P80-003 : ITR LSD
91005-P80-E31 : Differential ball bearings (x2) [Pic]

41xxx-Pxx-B00 : 80mm Differential shim (for use with the enclosed differential ball bearings [91005-P80-E31]) [Pic]
- use the 79.5mm diameter shim for the tapered roller bearings

Misc. Other & Replacement Parts:
91216-PH8-005 : Clutch Housing Mainshaft Oil Seal [optional or as needed]
91002-PS1-003 : Clutch Housing Mainshaft Bearing (28x60x15) [optional or as needed] [Pic]
91101-P80-008 : Clutch Housing Countershaft Bearing (33x60x20) [optional or as needed]
91205-PL3-A01 : Clutch Housing Axle Seal (35x56x8) [optional or as needed] [Pic]
72mm Mainshaft thrust shim [as needed]

23927-PG2-A00 : Mainshaft Spring Washer (28mm)
91205-PC9-711 : Gear Housing Axle Seal (40x62x8) [optional or as needed] [Pic]

91211-P21-008 : 1st Gear (Lower) Friction Dampener [optional or as needed]
91212-P21-008 : 2nd Gear (Upper) Friction Dampener [optional or as needed]
91105-P21-003 : 2nd Gear Needle Bearing [optional or as needed]
90202-PH8-000 : Countershaft Lock Nut (23mm) [Pic]
23926-P21-000 : Washer (23mm) [optional or as needed]
91003-P21-003 : Countershaft Ball Bearing [optional or as needed] [Pic]
91102-P21-003 : Countershaft Roller Bearing (25x52.2x15) [optional or as needed]

Start Procedure:
1.] Opening the Casing
Set the tranny bellhousing on 2'x4's to keep the input shaft from bottoming out.

Remove the VSS. Remove the (1) 10mm bolt. Twist/wiggle the VSS a little and pull up.

Remove the two plugs and 5/16" ball bearings on the bottom of the tranny that stake the 1st/2nd and 3rd/4th shift forks.

Casing bolt loosening pattern.

One of the casing bolts secures the reverse light switch to the casing.

Two more of the casing bolts secure the tranny hanger (Hanger A) to the casing.

You also need to remove the other tranny hanger (Hanger B) to get to one of the casing bolts.

All the bolts are the same length, so you don't need to worry about marking any odd-length bolts to their original locations.

Remove the 32mm sealing bolt with a 1/2" drive ratchet.

This is the snap ring under the 32mm sealing bolt. Expand it with a pair of snap ring pliers. You can spin the ring around to get better positioning on it.
Locked position

Unlocked position - You'll hear the countershaft drop when you've expanded the snap ring enough.

Remove the reverse idler gear shaft bolt on the top of the tranny casing. I forgot to do it before popping the casing open. Oops.

Pry here and the casing will come up and then you can pull it straight up off the bottom of the bellhousing.

A couple of shots of the gear sets. Differential - countershaft - mainshaft/input shaft (from left to right in both pics).

Inside of the tranny casing.

Tranny magnet just below the change holder.

All the hardware that should have come off the tranny to this point.

Reverse change holder needs to be removed by taking out those two 10mm bolts.

Reveerse idler gear and idler shaft after removing the reverse change holder.

Remove the reverse idler gear and shaft by pulling up and wiggling it out.

After removing the reverse idler change holder, gear, and shaft.

Checking a few clearances....maybe I'll elaborate later and put in the tolerance ranges.

2.] Removing the Gearset & Differential
Remove the change holder assy for the forward gears by taking out three 10mm bolts. Two at the bottom and one on the opposite side of the change holder.

Pull out the change holder shaft.
Edit: Lt. Dan GSR says not to pull the change holder shaft and to just remove the (3) 10mm bolts to remove the assy. He says it's hard to put back in if you do it that way. He would know better...I've only done one other tranny.

Change holder assy. I put the shaft back in after removing it.

The change holder uses different bolt lengths. One (lighter color) is shorter than the other two (darker).

After removing the change holder assy. Time to remove both the gearsets and shift forks.

The mainshaft, countershaft, and shift forks are removed as a whole unit. Hold the two shafts and three forks together and pull them upwards with a little finesse to get them to ease out.

These guys hang around after removing the gearsets. Spring washer (it's the concave one) on bottom and washer on top. (As seen in above diagram.)

Clutch housing after removing the gear sets and shift forks. You can now see the clutch housing counter and main shaft bearings.

Now remove the differential assy. Pull it straight up to get it out of the clutch housing.

Gear housing side of the differential.

Clutch housing side of the differential.

3.] Installing the New FD, LSD, and Differential Ball Bearings

Tapered roller bearings. You won't be using these kind on the LSD. It's recommended that you switch over to the enclosed differential ball bearings to make it easier to measure the clearance needed b/w the differential and gear housing.

You can see the separate outer race for the tapered roller bearings here in the clutch housing. There is a 2.5mm thick thrust shim directly underneath the outer race, sandwiched b/w the differential outer race and the axle seal.

The new ones differential bearings are enclosed and no longer use the separate outer race or the thrust shim behind the outer race in the clutch housing. Front and back view of the enclosed bearings shown here.

Remove the (10) 14mm bolts to separate the final drive gear from the differential: The bolts are reverse-thread, so it's righty-loosey, lefty-tightey. The only reason I separated the two was to reuse the bolts. If you buy (10) new ones and are installing a new differential and final drive, you won't have to mess with this part.

New ITR LSD and JDM ITR 4.785:1 final drive ring gear. Courtesy of Jeff (Lip) and Dave/Chad @ R&D Motorsports.

Put the new ring gear onto the differential.

Rotate the ring gear on the differential to get the holes to line up. It shouldn't be fussy and slide around as smooth as buttah.

Clean the bolts with brake parts cleaner to remove the oil.

Apply threadlocker to the (10) bolts.

I used a 14mm deep socket on a short extension to quickly thread the bolts in. Remember that the bolts are reverse-thread.

Clamp the differential/ring gear assy into a table clamp with two planks of wood. Torque the bolts to 74.5lb*ft. Hopefully your's is mounted to a table...unlike mine. I really had to fight it to torque the bolts down.

Lube up the differential bearing and differential with MTF. Place the the bearing onto the differential.

I used a a plank of wood to get it as far down as possible and then 1 5/8" socket to knock the bearing all the way down onto the differential.

Done with that clutch housing side.

Done with the gear housing side.

Something I noticed is that the enclosed bearings don't leave as much differential exposed as the old exposed bearings. I'm hoping that this it normal and maybe Dan or Willard will confirm this. It makes sense that it would be like that b/c the old bearings mate with an outer race that's in the tranny casing halves. The new ones don't have that outer race in the casing halves.

Old exposed differential bearings on gear housing side

New enclosed differential bearings on gear housing side

Before we check the differential-to-housing clearances to determine what new shim thickness we need, we need to remove the outer races interference press-fit into the housings.
I'm not sure if it's mandatory to remove the axle seals to hammer out the outer races, but since I had replacements already, I did it anyways. I used a nut driver and hammer to knock the axle seals outwards. They come out really easily, so you don't need to pound them really hard.
Clutch housing side

One punch and it'll push it out...

...and you can pick it up with your hand.

Gear housing side - removing the axle seal.

Flip the clutch housing over so you can hammer out the outer race on this side.

I used a seal installer to drive it out. A few gentle thwacks and it comes out pretty easily.

The shim (left) and outer race (right) - in order of assembly.

Drive out the outer race on the gear housing.

This side had two shims and then the outer race. Since we switched to the enclosed ball bearings, we will no longer use a 79.5mm shim. Instead, we'll only be using a single 80mm diameter shim on the gear housing and no shims on the clutch housing side.

This is how the outer race interfaces with the tapered roller bearings.

Put a little MTF on the outside of the ball bearing and gently put the differential assy into the clutch housing. Use one hand from underneath to support the differential to keep it from banging around when trying to let it drop down into the hole. It should just gently fall into the hole without any hammering. Altho, the manual has recommended it if you can't get it to drop it easily.

4.] Setting Differential Thrust Clearance

Put the gear housing back on to check the differential-to-casing clearance. Don't use any Hondabond to seal the casing.

Torque the bolts to 20lb*ft. Have another person hold the tranny while you torque them down, or do like I did b/c everybody else went out to dinner.

Make sure that the differential is seated all the way down into the casing before measuring. You can do this with a driver and hammer. This will help to ensure that you get an accurate reading.

Check the differential-to-casing clearance.

Specified clearance = 0.0mm-.10mm (0.000"-.004")

Insert feeler gauges here. I used angled feeler gauges to make the measurement easier.

Without an 80mm shim already in the tranny (b/c I didn't have one), I had to stack a couple of feeler gauges together to measure the clearance. These are the 4 that I narrowed it down to. I paired one of the three on top with the .021" feeler gauge to go up/down a thousandth.

.021"+.022" = .043" Too loose
.021"+.023" = .044" Slides in with a little drag
.021"+.024" = .045" Slides in with a little more effort
I'm gonna say that it's b/w .044" and .045". Then we do a little math to get the appropriate shim thickness to buy.
.044" - .004" = .040" shim
.045" - .004" = .041" shim

With that calculated shim thickness, we go to the shim table and pick out the shim with the thickness that matches .040"-.041" the best.
Shim K = .0413"
Using shim K, gives me a clearance of (.045" or .044") - .0413" = .0037" to .0027"....under our .004" target clearance.

I could also use Shim B to tighten up the tolerance by .0020" to get a final clearance of .0017" to .0007". I prefer to be on the tight side, so in this case, I'd recommend the B shim over the K shim.

When you get the new shim, use a pair of snap ring pliers to insert the shim into the recess. This is the shim K I just got installed.

Once again, put the gear housing back on, and test the differential thrust clearance.

In my case, I ordered the 80mm K shim (.0413"). What I found out was that it still had .007" of clearance when my calculations predicted a .0037" clearance.

So, I went back and looked at the chart and picked out another shim, shim L (.0453"). I also picked up a shim C (.0472") just in case. When I checked the thrust clearance with the C shim, it came out to .004". That whole ordeal was pretty odd, but it's something you should be aware of and ready to expect. I left it at that and moved on.

5.] Disassembling the Countershaft
Lock down the countershaft into the bench clamp. Use the 2'x4's in b/w the countershaft and clamp teeth to keep from marring the countershaft.

Unstake the countershaft lock nut as best as you can with a screwdriver or punch and hammer.

Use a pneumatic or electric impact gun and a 32mm socket to loosen the countershaft lock nut. It'll shear off any of the staking away when it busts loose, so you don't need to worry about the staking too much.

Remove the countershaft lock nut and spring washer. It's up to you whether or not you want to replace the spring washer or not, but it's mandatory to replace the lock nut.

Remove the press-fit countershaft ball bearing. The countershaft ball bearing is what locks into the retaining clip on the gear housing behind the 32mm sealing bolt.

Remove the countershaft roller bearing's outer sleeve first before installing the bearing puller.

Remove the press-fit roller bearing with the bearing puller.

Remove the 5th, 4th, 3rd, then remove 2nd gear, 1st-2nd gear synchros, and 1st gear as one. They should all just slide off, but in the case that they don't, you can use the puller in the same fashion as above to remove the gears.

After removing the gears and synchros, you'll be left with the countershaft, thrust shim, and needle bearings.

Gearset in order of removal from left to right.

You will not be reusing the first gear, first gear needle bearings, countershaft, and countershaft thrust shim anymore. You can pack that stuff up and sell it along with the differential and final drive ring gear.

Remove the friction damper and synchro hub/ring from the 1st gear. Those two items will be reused on the JDM ITR first gear, unless you choose to replace them as wear items. Clean them with brake parts cleaner and wipe them off with a clean, lintless rag before moving onto the next step.

6.] Assembling JDM ITR Countershaft

These are the parts that make up the 1st gear assy. From the top left, counter clockwise: JDM ITR needle bearings, JDM ITR ring collar, 1st gear (lower) friction damper [reused], synchro ring & spring [reused], JDM ITR first gear.

This is how the 1st gear assy pieces together:

The two needle bearings go on the ring collar.

Then the first gear slips over and around the ring collar & needle bearings.

The lower friction damper sits tight in the first gear.

The friction damper has a particular orientation that's dependent on the synchro hub. More on that later.

The synchro ring presses down onto the first gear.

Fully assembled first gear assy.

Now for the actual assembly of the countershaft.

Separate the ring collar & needle bearings and lower friction damper from the first gear assy.

Lube up the countershaft and ring collar first and then install the ring collar on the JDM ITR countershaft. You may need to twist it a little while pushing down on it to finesse it all the way down. It should slide all the way down to the top of the FD gear with minimal resistance.

The pair of needle bearing halves sit on the ring collar, and the first gear rides on the needle bearings. You can lube up and put the needle bearing halves onto the ring collar now or wait until you have the first two gears assembled before installing the needle bearings.

I find it easier to assemble the first gear, 1-2 synchro, and second gear into one piece before installing it on the countershaft.

Synchro hub - bottom side shown (this side faces towards the first gear assy

Take the 1st/2nd gear synchro hub, flip it upside, and set the 1st gear (lower) friction damper so that the tabs fall into the slots on the synchro hub.

Flip the first gear assy upside-down and mate it to the synchro hub so that the alignment tabs on the synchro ring match the slots on the synchro hub [Pic]. This will properly orient and seat the friction damper into the first gear. You can flip it back over and lift up the synchro hub and the friction dampener will be stuck into the first gear in the proper orientation.

This is the top side of the synchro hub. The three little dimples interface with the hooks on the upper friction damper.



writen by IN VTEC honda-tech