A transmission that slips, flares or shifts hard has plenty of possible causes, and only some of them live inside the transmission. RDI Power diagnoses and repairs diesel truck and motorhome transmissions at our Brooksville shop, about 21 road miles from the middle of Inverness Highlands South, and we find out which kind of problem you have before anyone quotes a rebuild.
Shifting complaints from Inverness Highlands South trucks that tow
The Citrus Tract campgrounds are next door, and if your truck pulls a camper or a boat there, it is asking the transmission for its hardest work. Towing multiplies heat. As fluid gets hotter it breaks down faster, and broken-down fluid lets clutches slip, which makes more heat still.
Watch for these:
- A delay or a clunk going into drive or reverse
- Engine speed flaring between shifts, especially climbing with a load
- A shudder at a steady cruise, as if the tires were crossing a washboard, often traced to the torque converter clutch
- A transmission temperature reading higher than it used to be on the same tow
- Fluid that looks dark or smells burnt, or spots under the truck
If you tow regularly, use the severe service interval for fluid and filters.
Limp mode on Pleasant Grove Road: call before the 21-mile trip
When a control module sees a problem it does not like, it may lock the transmission into a single gear to protect it. That is limp mode, and it does not say why it happened. A failed speed sensor, a wiring fault, low fluid and an overheated unit can all cause it. Some of those make a gentle 35-minute drive acceptable. Others mean every mile adds damage. If it happens on CR-581, park safely and call; a mobile technician can scan the truck where it stands, and we will choose between driving, towing or fixing it on site.
Rebuild or repair for an Inverness Highlands South transmission
Diagnosis comes first. We pull codes from the engine and transmission modules, watch live data on a road test, check the fluid level at the temperature the manufacturer specifies, and examine the fluid for color, smell and metal. Then we test solenoid and sensor circuits.
If the transmission is healthy inside, the fix may be a sensor, a solenoid, a valve body, wiring, a leaking cooler line or a software update, and that costs far less than a rebuild. When the damage is internal, the transmission is removed, disassembled, cleaned and inspected part by part, then rebuilt with new clutches, seals and whatever hard parts are worn, and reinstalled with the cooler flushed or replaced. In some cases a remanufactured transmission is the better value, and you get both options side by side.
Allison units in buses, medium duty trucks and diesel pushers deserve their own note. Many of them rack up long hours idling or creeping in traffic while the odometer barely moves, and that kind of service is hard on fluid. Fluid and filter changes on schedule, based on hours as well as miles, are the cheapest transmission repair there is.
We work on the 10R140, 6R140 and 5R110W in Ford Super Duty trucks, the 68RFE and Aisin in Ram trucks, Allison units in Duramax pickups, medium duty trucks, buses and diesel pushers, and manual gearboxes and clutches. Our post on 10R140 transmission repair covers the newest Ford unit. Our labor on transmission work for Inverness Highlands South customers is warrantied for 36 months or 36,000 miles.
Engine faults can mimic shifting faults, and the Inverness Highlands South truck repair page covers that side. Each step of the process is laid out on our truck transmission repair and rebuild page, and trucks based farther south on US-41 are covered by our Floral City transmission repair page.