XR4Ti Archived Tech Articles
Thanks to Neil Swanson of NSPS, for supplying me with the majority of the info seen here and to Allan Slocum for the use of the transmission ratios and part number list.
Prices that are given are the prices I paid. I may have paid more than needed, I know I paid more then I expected, but in my case I look for the lowest hassle first, price was second on my agenda. Starting out the process of buying parts and figuring out what I needed was sort of confusing, but I found out that a little confidence and some reading brought me up to speed. As I purchased parts and saw how everything fit together it was more understandable and everything then seemed to fall into place.
I can probably answer almost any question on this process, if not I can direct you to someone who can. I am by no means an expert on this for I have only done my swap, but I feel I have a good understanding of everything that has to be done. Feel free to email me: Ryan, email@example.com
Test out different ratios with my online RPM to MPH Calculator found in the "Calculators" section of the MerkurTech.com web page.
According to Neil the "best" way to go is to get a new World Class T5 with the 3.35 1st gear. The most "bolt-up" way is to use a T5 from a Turbo T-Bird or SVO Mustang, except for some drivers, these have less desirable ratios. The method I consider most affordable/desirable is to install a used T5 from a 5.0 Mustang.
Used 5.0 Transmission - Salvage yard - $550
Used 86 TurboCoupe Transmission and Bellhousing - auto parts trader publication - $250
If you get a used 5.0 Mustang T5, you may want to get it rebuilt and also change 5th gear to a 0.83. You may consider the 5th gear that comes on the 5.0 Mustang to be way too high for our cars. You will also need to have the input shaft turned down to fit the 2.3 trans pilot bearing, my machinist turned it to 0.590.
The stock shifter that should come with the used trans is okay, but a better idea is to get one with positive stops ($120 to $180 from Summit or Jeg's). The positive stops on the shifter prevent over shift into 2nd and 3rd gears, which can result in bending of the 1-2 and 3-4 shifter forks.
Also get a new transmission pilot bearing. The transmission I got came with both the neutral and backup switches and the wiring for them. I just cut and spliced the stock XR chassis wires with the new switches.
I did the transmission rebuild myself. This process is fairly easy. (The way these work really have a coolness factor too.) The most difficult part is pulling off some bearings and a few of the gears. Special tools needed are gear pullers, a dial indicator, dial/digital calipers and/or micrometer.
The spreadsheet below is a list of T-5 transmissions, their gear ratios, years of application and approximate torque rating.
The process of dropping out the old transmission was fairly easy. Some of the bolts were tight and I had to unbolt the sway bar from the body to get enough clearance to get the transmission out.
Upon installing the transmission I had to cut the opening in the floor for the shifter about 2"- 2 ½" forward (this is not required on all XR chassis). I placed a piece of rubber around the base of the shifter and mounted it to the body to seal off the opening in the floor. I used my auto center console piece, it was necessary to cut it forward a bit also. I then made a metal plate to cover the majority of the opening and a rubber boot to cover the rest.
A manual transmission shifter console will also work in this application as well. The shift boot is generally tight against the forward portion of the shifter hole opening. It was discovered that the European manual transmission console has the shifter hole moved forward allowing for more clearance around the shift boot. See the comparison photo below.
Note: the European console is installed and the North American console is the the photographer's hand.
5th Gear Parts - Hanlon - $186
WC Rebuild Kit - Hanlon - $170
Borg Warner T5 Service repair manual - Hanlon - $17
B&M "Ripper" Shifter - Ford SVO - $225
New Trans Pilot Bearing - Local Ford Dealer - $15
Labor for turning down input shaft - Local Machinist Friend - $3
Transmission Mount and Crossmember
Here I used my original crossmember and fabricated a bracket that bolts between the trans and crossmember. It may be easier to order one already set up from Rapido. The Rapido crossmember accepts most T-5 mounts (Anglin sourced one for an 87 5.0 Mustang with a T-5), which are generally in stock at auto parts chain stores for about $13.
Note that there was a running change in the floor pans of the XRs between 1986 and 1987. The later model cars had a wide tunnel to accomodate the all-wheel drive parts some European models and the earlier cars had a narrow tunnel. If you are going to order a crossmember, make sure you know which one you need.
Modifying stock crossmember and tranny mount - free
Rapido T-5 crossmember - $50 (approximately)
T-5 mount for Rapido crossmember - major autoparts chain store - $13
What ever way you decide to go you'll need a bellhousing, this can be acquired from any Thunderbird Turbo Coupe '86 or earlier model. Anything later than '86 has a hydraulic clutch, so they wont work. Along with this you'll want a new clutch release bearing. I also had to buy the clevis clips and pins that attach the clutch cable to a pivot arm on the bellhousing and the dust boot that covers the release lever.
Bellhousing get it used or new.
Used Bellhousing - Salvage yard - $75
New Clutch Release Bearing - Local Ford Dealer - $38
New Dust Boot - Local Ford Dealer - $21
New Clevis and Pins - Local Ford Dealer - $17
You can get this from any manual 2.3 Thunderbird, Mustang or Merkur. All 2.3 flywheels are the same. The attaching bolts for the manual flywheel are longer then for the auto flexplate so you'll also need those. These bolts are self locking and I'm guessing only Ford or maybe a salvage yard has them.
Get it used or new.
Used Flywheel - Salvage yard - $75
Clutch Disc and Pressure Plate
There are many clutches available, I've heard a lot about how Centerforce clutches make noise. I used the clutch disk and pressure plate for an 86 SVO Mustang, Neil said he uses these and even at 300 horse it doesn't slip.
Get them new from Ford SVO Motorsports, part numbers:
Clutch Disk # M-7563-A221 - $74
Pressure Plate # M-7550-A221 - $80
Clutch Alignment tool - Local Auto Shop - $2
Get this from any manual XR4. If you can get it used do it, it's $90 new from ford, and after already getting mine I noticed BAT has them for $19.
You'll also need to get the 2 inch "dogbone" cable which connects the pivot arm on the bellhousing to the clutch release lever. The clutch cable needs a little bit of grinding to fit into the clevis clips. The OEM clips put the end of the cable too close to the lever on the bellhousing, in this case I made an extender to space the cable a bit farther away from the lever.
Cable - get it new or used:
Used Clutch Cable - IMON Member - $30
New dogbone Cable - Local Ford - $14
Speedometer Cable and Gear
The speedometer cable from the automatic XR4Ti works, the only thing you'll need is the right gear so your speedo reads correctly. Get the gear from Ford. The gear you'll need to buy for the end of the speedo cable is called the "driven gear". To find out what gear you will need you'll have to do one of two things, either use my online program that will tell you what gear you need or do some math.
New Driven Gear - Local Ford - $14
Use my online Driven Gear Calculator to figure out what gear you need or following are the instructions you need if you decide not to use my program.
To find what "driven gear" you'll need first you need to know your "tire revolutions per mile". Here are some tire sizes and their corresponding revs per mile.
Take your "tire revolutions per mile" and multiply it by the "drive gear teeth". The drive gear is inside your transmission on the output shaft. The normal gear teeth are:
6 - for some 4-cyl T5 transmissions
7 - for most '83-'89 V8 5.0 Mustang transmissions
8 - for '90-'95 Mustang GT and 5.0L LX transmissions
Take the number you have now and multiply it by your "axle ratio".
3.36 for an auto XR4
3.64 for a manual XR4
Lastly take the number you now have and divide it by 1000. This will give you your desired "driven gear" size:
Here is the formula that you just used:
Clutch and Brake Pedal Assembly
Get this used from any manual XR4. Someone said that changes were made to the mounts for this every few years. If you can, just to be safe get the pedals from the same model year as your car. Mounting the pedals is just "bolt up" there is already a hole in the firewall for the clutch cable to go through.
Used pedals - Salvage yard - $35
With this you have a couple of options. Mike Steere sells these for about $400, BAT sells one for about $500, you can have one made, or adapt yours. To adapt yours you'll need a T5 Slip yoke, weld yoke, U-joint, and the following information I had a local maching shop cut, weld and balance mine. The shop also supplied the parts.
Parts and Labor for adapting - Local Shop - $195
Total shaft length from tip of front yoke to rear flange: 55 inches
Rear joint center to middle joint center: 31.25 inches
This won't change but you may want to know...
Middle joint center to front joint center: 16 inches
Length of the yoke from the tip to joint center: 6.5 inches (mine was 6 inches)
Really all that is done is the XR4 end is cut off and the T5 weld yoke is welded on and the new U-joint and slip yoke are installed. As long as the 16 inch distance is held from center to center of the middle joint to the front joint you should be OK. UNLESS, your yoke isn't 6.5 inches. If not make the allowances needed.
There is a little +- in the total length. But only at the front end i.e.: the front may be 15.75 or 16.25. Don't allow any fudge in the middle. You still have a center mount that needs to fit.
Ford SVO Motorsports
44050 North Groesbeck Highway
Clinton Township, MI
Phone (810) 468-1356 for a catalog
Your local ford dealer can get these parts.
Hanlon Motorsports, www.hanlonmotorsports.com
3621 ST Peters Rd
St Peters, PA
British American Transfer Inc. (BAT), www.batinc.net
2263 Industrial Blvd.
Phone (941) 355-0005
Fax (941) 355-4683
RAPIDO GROUP, www.rapidogroup.com
80093 Dodson Road
Tygh Valley, Oregon
Phone (541) 544-3333
Fax (541) 544-3100
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Published by Chris Anglin.