45RFE 4WD transmission

Here’s an enhanced, well-supported guide specifically for the 45RFE 4WD transmission used in your 2007 Dodge Ram 1500 with the 4.7L:

 1. Transmission Overview

• Known as a “4-speed” but internally built with 3 planetary gearsets, using one as a bypass gear → mechanically similar to the 45RFE 4WD transmission

• Fully electronically controlled, relying on TCM, solenoids, and pressure sensors.

 2. Common Symptoms & Sources from Owners

• Delayed or hard up‑shifts, especially with moderate throttle—often indicating worn solenoids or valve body issues

• Limp Mode / stuck in 3rd due to TCM detecting faults—sometimes resolver by sensor, solenoid or TCM reflash/configuration .

• Gear loss (e.g., 1st or 4th) may be caused by a broken snap ring inside the transmission—even with minimal damage visible

• Fluid filter failure (especially earlier “ventless” designs) can cause sudden loss of gear engagement—install upgraded vented filters to fix .

 3. Maintenance & Rebuild Recommendations

1. Fluid & dual filter service every 50–75k miles using ATF+4 ONLY—drop the pan, replace both sump and cooler filters, seal with high-temp RTV

2. Valve body and solenoid pack rebuild—OEM or upgraded kits (TransTec, Sonnax, Raybestos) help prevent leaks and restore shift quality TCM Quick Learn / reflash after any major work or symptoms—required for reprogramming shift strategies and resolving limp mode.

3. Internal rebuild, if symptoms like repeated shift loss, metal debris, or broken snap rings persist—Master rebuild kits for 45RFE 4WD transmission include all seals, clutch packs, pistons, filters, and heavier-duty parts:

   • TRANSTAR/TransTec kits: ~$450–540 FFC Imports “Super Master” kits: comprehensive overhaul ~1999‑up Monster Transmission “Mega Monster” kits (2007‑up, rated ~500 hp/450 lb-ft): ~$2,500

 4. Diagnostic & Repair Flow

5. Budget & Kits Overview

• Fluid + filter service: ~$150–300

• Solenoid/valve body rebuild: ~$600–1,400

• Master rebuild kit: ~$450–540; heavy-duty kits $2,500+

• Rebuild labor: $1,500–3,000 (varies by quality of service)

 Community Wisdom from Reddit

 Conclusion

The 45RFE 4WD transmission can be very reliable when well-maintained. Start with fluid/filter changes and ensure correct ATF+4, rebuilt solenoids, and a proper TCM relearn. If shifting issues persist—or internal damage is suspected—a full rebuild with a master kit is the best path forward.

Let me know if you’d like help choosing a specific rebuild kit, step-by-step instructions, TCM tool suggestions, or sourcing the updated filters!

Here’s a refined and well-supported guide specifically tailored for the 45RFE 4WD transmission, as found in your 2007 Ram 1500 with the 4.7L.

 What is the 45RFE 4WD transmission (4WD)?

• 4-speed automatic (internally 3 planetary sets)—mechanically similar to the 45RFE 4WD transmission and falls under Chrysler’s RFE family Electronically controlled by the TCM, using adaptive shifts learned via solenoids and pressure sensors.

 Symptoms & Common Causes

1. Soft/Harsh Delayed Upshifts

• Often caused by worn solenoid packs or clogged valve bodies.

• Reddit users frequently report issues activating only under moderate throttle.

2. Limp Mode (Stuck in 3rd gear)

• Triggered by TCM detecting faults. Common fixes include: sensor cleaning/replacement, solenoid pack swap, or TCM reflash .

3. Gear Loss (1st/4th)

• Usually due to broken snap rings or lack of hydraulic pressure — requiring internal rebuild.

4. Dual Filter/Pan Failures

• Original “ventless” filters can collapse or tear, losing hydraulic pressure. Upgraded vented filters address this issue .

45RFE 4WD transmission Maintenance Strategy

1. Fluid & Dual Filter Change

   • Drop pan every 50–75k miles, use Mopar ATF+4 only, seal with RTV, install updated 4WD filter Valve Body & Solenoid Pack

   • Replace or rebuild with OEM or improved kits (TransTec, Sonnax). Include gasket upgrades and accumulator pistons to solve leak issues TCM “Quick Learn” Procedure

   • Reset adaptive learning post-service. Follow exact steps for first N→D upshifts, 2–3, 3–4 shifts, etc. Requires a scan tool or dealership

2. Internal Rebuild (If Problems Persist)

   • Symptoms like snap rings, slipping bands, or debris call for a full rebuild.

   • Master kits available:

     • OPT Banner Box kit ~$310

     • FFC Imports 4WD master kit ~$300

 Practical Procedure & Budgeting

Tips from Real Owners

 Recommended Next Steps

1. Start with a pan drop, filter upgrade, and fluid service using ATF+4.

2. Replace solenoid pack, gaskets, and accumulator pistons.

3. Perform the TCM Quick Learn, per factory guidelines.

4. Test drive: monitor for smooth shifts, limp mode, or gear issues.

5. If problems persist, proceed to internal rebuild using a master kit.

Let me know if you’d like part numbers, step-by-step Quick Learn instructions, or help sourcing a quality rebuild kit!