Jeep T4 Transmission For Sale: Your Comprehensive Guide

Jeep T4 Transmission For Sale: Your Comprehensive Guide jeeps.truckstrend.com

The iconic Jeep CJ series has long been synonymous with rugged adventure, off-road prowess, and a no-nonsense approach to motoring. At the heart of many of these beloved vehicles, particularly from the early 1980s, lay a robust yet sometimes misunderstood component: the Jeep T4 manual transmission. For enthusiasts, restorers, and those facing a mechanical dilemma, the search for a "Jeep T4 Transmission For Sale" is a common quest. This article serves as your definitive guide, delving into everything you need to know about this classic gearbox, from its history and characteristics to where to find one, what to consider before buying, and how to ensure a successful purchase.

Understanding the Jeep T4 Transmission

Jeep T4 Transmission For Sale: Your Comprehensive Guide

The Borg-Warner T4 is a 4-speed manual transmission that was a common fixture in Jeep CJ-7 and CJ-8 Scrambler models, primarily from 1982 to 1983, often paired with the 2.5L Iron Duke four-cylinder or the 4.2L (258 cubic inch) inline-six engine. It succeeded the earlier T176 and was itself quickly replaced by its 5-speed sibling, the T5, and later by the AX-15.

Key Features and Specifications:

• Type: 4-speed manual, synchronized in all forward gears.
• Case Material: Aluminum, contributing to a lighter overall weight compared to some predecessors.
• Gear Ratios: Typically around 4.02:1 (1st), 2.37:1 (2nd), 1.49:1 (3rd), 1.00:1 (4th, direct drive), and 4.02:1 (Reverse). These ratios were well-suited for the engines it was mated to, offering decent low-end torque for off-roading and adequate highway manners for its time.
• Input Shaft: 10-spline.
• Output Shaft: 21-spline, designed to mate with the Dana 300 transfer case.



• Bellhousing: Usually featured the AMC bolt pattern.

Strengths:
For its era, the T4 was a relatively lightweight and compact transmission. Its direct 1:1 fourth gear made it efficient on the highway. When properly maintained and not subjected to excessive abuse (especially with larger tires or more powerful engines), it could be a reliable unit for light to moderate off-roading and daily driving. Its widespread use in CJs means that parts and knowledge are still available within the enthusiast community.

Weaknesses:
The T4’s primary limitations stem from its aluminum case and internal design, which make it less robust than heavy-duty truck transmissions or later Jeep units like the AX-15. Common issues include:

• Synchro Wear: Especially between 1st and 2nd, and 3rd and 4th gears, leading to grinding shifts.
• Bearing Failure: Can manifest as noise or excessive shaft play.
• Case Cracking: More susceptible to damage under severe stress compared to cast iron units.



• Limited Power Handling: Not ideal for highly modified engines or extreme rock crawling, where higher torque loads are encountered.

Distinguishing a T4 from a T5 (its 5-speed counterpart) can be crucial. Visually, the T5 is slightly longer and, of course, has an additional shift gate for fifth gear. Internally, the T5 often had slightly different gear ratios, including an overdrive fifth gear.

Why Buy a Jeep T4 Transmission?

The decision to purchase a T4 transmission typically falls into one of several categories:

1. Authentic Restoration: For owners of classic 1982-1983 CJ-7s or CJ-8s, finding an original T4 is essential for maintaining the vehicle’s historical accuracy and value.
2. Direct Replacement: If your existing T4 has failed beyond economical repair, replacing it with another T4 is the simplest and most straightforward solution, requiring no modifications to the drivetrain or crossmember.
3. Cost-Effectiveness: Compared to a complete transmission swap (e.g., to an AX-15 or NV3550), which often involves new bellhousings, clutch components, transfer case adapters, driveshafts, and shifter modifications, replacing a T4 with another T4 is significantly cheaper.
4. Simplicity: For those who appreciate the straightforwardness of a 4-speed manual and don’t require an overdrive gear or extreme durability for heavy-duty use, the T4 fits the bill.

Where to Find a Jeep T4 Transmission For Sale

Locating a T4 can be a treasure hunt, but several avenues typically yield results:

• Online Marketplaces:

  • eBay: Often has a selection of used, rebuilt, and sometimes new old stock (NOS) T4s. Be wary of sellers with poor ratings.
  • Craigslist & Facebook Marketplace: Excellent for local finds, potentially reducing shipping costs. Search in wider geographical areas. Look for "Jeep parts," "CJ transmission," or "T4."
  • Specialized Jeep Forums & Groups: Websites like JeepForum.com, IH8MUD.com (while primarily Toyota-focused, often has a general classifieds section), and dedicated Facebook groups for classic Jeeps are goldmines. Members are often enthusiasts looking to sell good parts to fellow hobbyists.

• Specialized Jeep Parts Dealers: Companies that specialize in vintage or replacement Jeep parts may carry rebuilt T4s or used units that have been inspected. These typically come with a higher price tag but often include a warranty.

• Salvage Yards/Junkyards: For the adventurous and budget-conscious, visiting or calling local junkyards that specialize in older vehicles can be fruitful. You might find a T4 pulled from a donor CJ, though its condition will be a gamble.

• Transmission Rebuilders: Local or national transmission shops that specialize in manual transmissions might have rebuilt T4s for sale, or they may be able to source a core and rebuild it for you.

Key Considerations Before Buying

Purchasing a used or rebuilt T4 requires careful evaluation to avoid costly mistakes.

1. Condition is Paramount:

   • Used: Ask for detailed photos and videos. Look for cracks in the aluminum case, especially around mounting points. Check for excessive input or output shaft play (a little is normal, a lot is bad). Inquire about the fluid condition when it was removed (burnt smell, metallic flakes indicate trouble). If possible, rotate the shafts by hand to feel for grinding or resistance.
   • Rebuilt: A reputable rebuilder will offer a warranty (e.g., 90 days to 1 year). Ask what components were replaced (bearings, synchros, seals, gears).
   • New Old Stock (NOS): Extremely rare and expensive, but essentially a brand-new unit.

2. Completeness: Does the sale include the bellhousing, shifter tower, shifter stick, and transfer case adapter? Often, these components are sold separately, adding to the overall cost. Ensure the bellhousing bolt pattern matches your engine (AMC straight-six or four-cylinder).

3. Compatibility: Double-check the input shaft spline count (10-spline for T4) and the output shaft spline count (21-spline for Dana 300). While most T4s were consistent, confirming ensures a direct fit.

4. Price vs. Value: A very cheap T4 might be a core unit requiring a full rebuild, which can easily exceed the cost of a moderately priced, functioning used unit or even a professionally rebuilt one. Factor in potential rebuild costs if you’re buying a questionable used unit.

5. Shipping Costs: Transmissions are heavy. Get a shipping quote upfront, as it can significantly impact the total price, especially if buying from a distant seller. Local pick-up is often preferable.

6. Seller Reputation: Check online reviews, forum feedback, or eBay seller ratings. A reputable seller will be transparent about the transmission’s condition and history.

Tips for a Successful Purchase

• Ask Detailed Questions: Don’t be shy. Inquire about the mileage on the unit, the reason for its removal, its last service, and any known issues.
• Request Visual Evidence: Photos of all sides, the input and output shafts, and the inside of the bellhousing are crucial. A video of the shafts rotating can provide clues about bearing health.
• Verify Fitment: Confirm that the transmission will bolt directly to your engine and transfer case before committing. Have your vehicle’s exact year, engine, and transfer case model ready.
• Budget for Ancillary Parts: Even with a good transmission, you’ll likely need new gaskets, seals, fresh fluid, a pilot bearing, and possibly a new clutch kit if you’re doing a full replacement.
• Consider a Pre-Purchase Inspection: If buying locally, and the seller agrees, have a mechanic familiar with Jeep transmissions inspect the unit.

Installation and Maintenance

Once you’ve secured your T4, proper installation and ongoing maintenance are key to its longevity.

• Installation: This is a heavy component. Ensure you have the right tools (transmission jack) and assistance. Proper alignment of the input shaft with the pilot bearing and clutch splines is critical.
• Fluid Type: The T4 typically uses GL-4 manual transmission fluid, not standard gear oil (like GL-5) which can be corrosive to its brass synchros. Always check your Jeep’s factory service manual or a reliable Jeep resource for the correct fluid specification and capacity.
• Regular Fluid Changes: Like any manual transmission, regular fluid changes (every 30,000-50,000 miles or as recommended) are vital for cooling, lubrication, and removing wear particles.
• Listen to Your Jeep: Pay attention to any new noises (whining, grinding), difficulty shifting, or popping out of gear. Addressing minor issues early can prevent major failures.

Potential Challenges and Alternatives

While the T4 serves its purpose, its limitations can lead to challenges:

• Scarcity of Good Units: Finding a low-mileage, perfectly functioning T4 that doesn’t require a rebuild can be difficult as these transmissions age.
• Rebuild Costs: A full professional rebuild can be expensive, sometimes approaching or exceeding the cost of a used T5 or even an AX-15 conversion kit.
• Performance Limitations: For Jeeps with larger tires, more powerful engines, or those frequently engaged in demanding off-roading, the T4’s strength may be insufficient, leading to premature wear or failure.

Alternatives to a T4:
If you find the T4’s limitations or the difficulty in finding a good unit prohibitive, consider these common swaps:

• Borg-Warner T5 (5-speed): A direct bolt-in replacement for the T4, offering an overdrive gear for better highway mileage. Stronger than the T4 but still not considered heavy-duty.
• Aisin-Warner AX-15 (5-speed): A much stronger and more durable transmission, common in later YJs and XJs. Requires an adapter for the transfer case and often a new bellhousing and clutch kit when swapping into a T4-equipped CJ.
• New Venture NV3550 (5-speed): Similar strength to the AX-15, also requiring adapters.
• SM465 (4-speed, granny low): A very heavy-duty, cast-iron truck transmission with an extremely low 1st gear. Requires significant modification (bellhousing, driveshafts, crossmember) but is nearly indestructible.

Choosing an alternative often depends on your budget, mechanical skill, and the intended use of your Jeep.

Jeep T4 Transmission For Sale: Estimated Price Table

Prices can vary significantly based on condition, completeness, seller, and market demand. This table provides a general estimate.

Condition	Source	Estimated Price Range (USD)	Notes
Used	Junkyard / Private Seller	$150 – $400	"As-is," condition unknown. May require full rebuild. High risk, low cost. Often requires self-removal.
Used	Online Marketplace / Forum	$300 – $700	Pulled from a running vehicle, some history available. May still need seals, minor repairs, or a full rebuild depending on inspection. Freight shipping adds significant cost.
Rebuilt	Specialized Parts Dealer	$800 – $1,500+	Professionally rebuilt with new wear parts. Often includes a limited warranty (e.g., 90 days – 1 year). Best balance of reliability and cost for a direct replacement.
New/NOS	Extremely Rare	$1,500+ (if found)	"New Old Stock." Very unlikely to find. If available, typically from a vintage parts supplier or a very rare auction.
Core Unit	Rebuilders / Private Seller	$50 – $200	Non-functional unit suitable for rebuilding. Only for those planning a full teardown and rebuild.

Note: Prices do not include shipping, installation, or ancillary parts like clutch kits, pilot bearings, or new fluid.

Frequently Asked Questions (FAQ)

Q: What Jeeps came with the T4 transmission?
A: The T4 was primarily used in Jeep CJ-7 and CJ-8 Scrambler models from 1982 to 1983, typically paired with the 2.5L Iron Duke 4-cylinder or the 4.2L (258 ci) inline-six engine.

Q: How can I tell if I have a T4 or T5?
A: The easiest way is to count the gears. A T4 has 4 forward gears, while a T5 has 5 (with an overdrive 5th gear). Visually, the T5 is slightly longer. Both are aluminum case transmissions.

Q: Is the T4 a good transmission?
A: For its intended purpose and era, it was adequate. It’s relatively lightweight and simple. However, it’s not considered heavy-duty and is known for synchro wear and being less robust than later transmissions like the AX-15, especially with larger tires or more powerful engines.

Q: What are common T4 problems?
A: Common issues include worn synchronizers leading to grinding gears (especially 1st-2nd and 3rd-4th), bearing noise, and susceptibility to case cracking under heavy stress.

Q: Can I swap a T4 for an AX-15?
A: Yes, it’s a popular and common swap to gain a stronger 5-speed transmission. However, it’s not a direct bolt-in. It requires a different bellhousing, potentially a new clutch, a different transfer case adapter, and possibly driveshaft modifications.

Q: What fluid does a T4 use?
A: The T4 typically requires a GL-4 rated manual transmission fluid. Do not use GL-5 gear oil, as its sulfur-phosphorus additives can be corrosive to the brass synchronizers common in older transmissions like the T4. Always check your specific vehicle’s service manual for the exact recommendation.

Q: How much does it cost to rebuild a T4?
A: The cost to rebuild a T4 can vary widely depending on parts availability, labor rates, and the extent of damage. Generally, a professional rebuild can range from $600 to $1,200 or more, excluding removal and installation. This is why comparing the cost of a rebuild versus a professionally rebuilt unit for sale is crucial.

Conclusion

The Jeep T4 transmission holds a significant place in the lineage of classic CJ Jeeps. For those seeking to restore authenticity or simply replace a worn-out unit, understanding the T4’s characteristics, potential pitfalls, and available options is crucial. While it may not be the strongest or most advanced transmission ever made, a well-maintained or properly rebuilt T4 can continue to provide reliable service for the right application. By carefully considering its condition, source, and your budget, and by being prepared for potential ancillary costs, you can successfully navigate the market for a "Jeep T4 Transmission For Sale" and keep your beloved CJ rolling down the trail for years to come.