Eaton Fuller
Transmission Tools

A Fuller twin-countershaft box is not hard to work on, but it is unforgiving of improvised tools. The jobs that go sideways in a heavy truck shop are almost always the same handful: an input bearing pried off with a bar that chips the drive gear teeth, a countershaft bearing walked off crooked with a two-jaw puller that scores the journal, a countershaft that jumps a tooth during main box assembly, or a case bearing race pulled cocked that gouges the bore.

Each of those has a dedicated Eaton service tool, and each of those service tools has an aftermarket equivalent that costs a fraction of a shaft, a case, or a second teardown. This guide walks through which ones are worth owning, matched to the job you are actually doing.

Match the Tool to the Job

Input Shaft Bearing Pullers

This is the tool most shops buy first, because the input bearing is the one people try to beat off. The bearing sits behind a snap ring at the front of the case, and the classic mistake is levering against the snap ring groove or the gear itself. That is how drive gear teeth get chipped and a simple bearing job turns into a new main drive gear.

A proper puller captures the bearing from behind with a split collar, holds the collar closed with a band or ring, and uses a forcing screw centered on the end of the shaft to draw the bearing straight off. The pull is slow and square, so the inner race never cocks on the journal.

What to check before you buy

• Shaft size. The common pullers are made for 1-3/4 inch and 2 inch input shafts.
• Series exclusions. The pullers we carry do not fit the RT600 / 6600 series. If that is your box, these are the wrong tool.
• What is included. Bearings and snap rings are not part of the tool kit. Order the bearing separately.

We stock two versions: the 4308011-replacement input shaft bearing puller kit (welded tube, split collar, retaining band and forcing screw) and a hardened steel input shaft bearing puller listed for FRO, RTLO, FR and Roadranger families and UltraShift Plus units on the same shafts. Both cover the 1-3/4 and 2 inch shafts.

Countershaft Puller and Timing Block

Twin-countershaft boxes live or die on countershaft timing. During main box assembly, the upper countershaft wants to rotate the moment you let go of it, and if it jumps a tooth while the mainshaft goes in, the box will not shift right and has to come back apart.

The countershaft bearing puller and support set covers both halves of that job. The puller (RR1014TR style) grips behind the front countershaft bearing race on FR-series main boxes and pulls it square. The support block (RR1013TR style) sits in the case and holds the upper countershaft where you timed it while you land the mainshaft and gear stack on RT-series boxes.

It fits FR-series and RT-series Roadranger layouts. A mid-range Fuller is a different build, so confirm the designation on the tag before you order.

Roadranger Slide Hammer Adapter Kit

Some pulls cannot be done with a bearing splitter or a punch: output shaft seals, bearing races seated in the case, and the reverse idler shafts on FR-series boxes, which have no shoulder to grab. The Roadranger slide hammer adapter kit is the aftermarket version of the Eaton RR1011TR set: a slide hammer plus four adapters, one for output seals, two for case bearing races, and one for FR reverse idler shafts.

Technique matters more than force here. Seat the adapter square behind the part and work the weight in short strokes. If a race starts to tip in the bore, stop and reset it. A cocked race will gall the aluminum on the way out.

Clutch Cross Shaft Bushing Driver

Worn cross shaft bushings show up as a sloppy clutch pedal, a release fork that will not adjust out, and uneven release bearing travel that eats the release bearing and the clutch brake. When the shaft is out for a clutch job, replace the bushings.

The trick is getting them in straight. A socket and hammer catches one edge and crushes or shaves the bushing, and then the shaft binds. The stepped cross shaft bushing driver pilots inside the new bushing and drives on its edge, so the force goes straight down the bore. Housings vary by model and year, so confirm the bushing size first.

Getting the Box Out Safely

Lightning series transmissions are heavy and top-heavy with the shift tower on. Balancing one on a generic flat jack head is how a box rolls as you back it off the input shaft. The OTC 528150 Lightning jack adapter bolts to the saddle of an OTC 5019A transmission jack and cradles the case so it sits flat and locked. It is an adapter only and needs the 5019A jack.

If you are still choosing a jack, read our heavy-duty truck transmission jack guide first. Buy the jack around the heaviest box you will ever pull.

Air System Parts: Range and Splitter Valves

Plenty of Fuller "transmission problems" are air problems. Before anyone pulls a box, sort out which shift is failing:

• Range will not shift, shifts slowly, or sticks in low or high range, with a steady air leak at the side of the case: suspect the range slave valve. The K-2424 pattern range slave valve kit is listed for the RTLOF-18718B 18-speed, uses 1/8 inch NPT ports, and comes with the gasket and mounting bolts.
• Splitter is lazy, drops back to low split under load, or hisses at the auxiliary housing: suspect the splitter valve. The K3331 splitter valve kit fits RTLO14718, RTLO16718 and RTLO18718 plus the RTLOF B-model overdrive variants, and includes the O-rings and elbow fitting.

Rule out a cracked air line, a bad shift knob, and low regulated air pressure first. Both valves are on-truck repairs: drain the air system, tag the lines, swap the valve, then build air and listen for leaks while you cycle the shift with the engine off. Always compare the part number on your old valve against the cross references before you order.

Common Mistakes

• Ordering by truck, not by transmission. The same tractor model can carry different Fuller boxes. Read the tag on the case.
• Assuming every Fuller takes the same input puller. RT600 / 6600 series is the known exception.
• Skipping the timing block on an RT rebuild. It costs less than the labor to tear the main box down a second time.
• Prying races out of the case. The case is the most expensive part in the box. Pull races straight with the right adapter.
• Replacing valves before checking air supply. A leaking line or weak regulator will make a new valve act just like the old one.

FAQ

Will an input shaft bearing puller work on every Eaton Fuller?

No. The pullers we carry are made for 1-3/4 inch and 2 inch input shafts and do not fit the RT600 / 6600 series. Check your shaft size and the model tag on the case before you order.

What does the countershaft support block actually do?

On RT-series main box assembly it holds the upper countershaft in the position you timed it, so the timing marks stay lined up while you install the mainshaft and gear stack. Without it the countershaft can rotate and jump a tooth.

My truck will not shift range. Is it the transmission?

Often it is the air system. A failed range slave valve causes no range shift, slow range shifts, or a box stuck in low or high range, usually with an air leak at the side of the case. Check the air lines, the shift knob and the regulated pressure, then the slave valve, before you pull the transmission.

Do I need the OTC 5019A jack to use the 528150 adapter?

Yes. The 528150 is an adapter plate that bolts to the saddle of the OTC 5019A transmission jack. It does not work as a standalone cradle.