F99975 Gearbox Rear Cover

The F99975 Gearbox Rear Cover is a key protective and sealing part for the gearbox system of HOWO heavy-duty trucks (tractor, dump, cargo trucks). It covers the gearbox's rear end, sealing the internal lubricating oil to stop leaks and protecting the gearbox's inner gears, bearings, and synchronizers from dust, mud, and foreign stuff-this keeps the gearbox lubricated and running smoothly, which is super important for easy gear shifting and making the gearbox last longer.

We use good materials and precise machining to make it: the cover body is high-strength HT250 cast iron-stiff and tough against impacts. The sealing surface is precision-ground, so the flatness error is no more than 0.05mm. The matching gasket is imported nitrile rubber-resists oil and high temps. The mounting holes, bolt specs, and overall size fit the original HOWO gearboxes (like HW19710, HW20716) exactly, so it installs with no gaps. It handles tough conditions-engine high-temperature radiation (up to 120℃), gearbox vibration (5-500Hz), and road mud/water-without the cover cracking, gasket aging, or mounting holes deforming. Swapping it is easy: no need to modify the gearbox or other parts, just take off the old cover's bolts, clean the sealing surface, put the new cover on with the matching gasket, and tighten the bolts to 25-30N·m in a crisscross order. Before shipping, we test 'em strict: check sealing (no leaks at 0.3MPa), test flatness, and do a 1.5m drop test-so it's reliable.

Great sealing: The precision-ground surface and imported nitrile rubber gasket make a tight seal, so the gearbox doesn't leak oil even after long-term vibration-leaks 90% less than ordinary rear covers.

Strong structure: The HT250 cast iron cover is stiff enough to take hits from things like stones without cracking, and it won't deform from the gearbox's internal pressure.

Perfect for HOWO: Made exactly to HOWO's original gearbox design-mounting hole spacing, cover thickness, and bolt hole size all match the original part. No adapter plates or new bolts needed during installation-saves 25% maintenance time vs universal rear covers.

Oil & rust resistant: The imported gasket resists gearbox oil (like GL-5) for over 3 years, and the cast iron cover has anti-rust coating-resists road salt and rain rust, lasting over 200,000 km.

This Gearbox Rear Cover (Model: F99975) is only for HOWO heavy-duty trucks with specific original gearboxes-A7, T7H, T5G models matching HW19710, HW20716, HW13710 gearboxes. It won't work on other HOWO gearboxes (like HW15710) or other brands (FAW Jiefang, Dongfeng Tianlong). Those have different gearbox rear structures, mounting holes, or cover sizes-this rear cover won't fit or work.

Product Model: F99975

Applicable vehicles: HOWO A7/T7H/T5G with HW19710/HW20716/HW13710 gearboxes

Type: Gearbox rear cover (cast iron + nitrile rubber gasket)

Function: Seal gearbox oil, protect internal parts from foreign matter

Material: Cover (HT250 cast iron, anti-rust); gasket (imported nitrile rubber); sealing surface (precision ground)

Installation: Direct replacement-fits original gearbox holes, bolts

Working conditions: ≤0.3MPa sealing pressure; -30℃~120℃; ≤0.05mm flatness error; ≥200,000 km life

Q1: Works on HOWO trucks with HW15710 gearboxes?

A1: No-HW15710 has a different rear structure and mounting holes. It won't fit, causing oil leaks. Get the rear cover for HW15710 instead.

Q2: Gearbox leaking oil after new cover install?

A2: First, clean the sealing surface (no oil/debris/scratches). If clean, check if the gasket is placed right (no reverse/misalignment). If the gasket is good, tighten bolts in a crisscross order to 25-30N·m. Still leaking? Replace the cover (rare defect).

Q3: How to maintain the gearbox rear cover?

A3: 1. Check bolts for looseness every 10k km (tighten crisscross); 2. Inspect gasket for aging every 30k km (replace if damaged); 3. Clean the cover surface often to protect the anti-rust coating.

Q4: Need to replace the gasket with a new cover?

A4: Yes, definitely. Reusing old gaskets causes leaks-use the new matching gasket that comes with the cover.

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