Grease for the Ace and Aceca Suspension and Chassis

Start with the chassis plate

If your car carries a lubrication chart, or a plate listing lubricants by their period trade names, that is the closest thing to a factory answer you will find and it is the first place to look. The archive cannot tell you whether every Ace and Aceca carries one, or what it says, because it has not seen one. A forum member suggested that photographs of chassis plates might give a clue, but the page he pointed to shows a brass chassis number plate and lists no lubricants. If you have a car whose plate or handbook does name a grease, the archive would be glad to hear what it says, because that is the gap on this page.

The originals are obsolete, match by type

Where a period grease is named, it is likely to be out of production, so you match by type rather than by name. Castrol's classic oils arm publishes the modern products that supersede its own older greases, which is a practical way to trace a like for like replacement. For other period brands you are matching a specification rather than a name.

The type owners use, and what it rests on

In practice, owners grease these points with a general purpose lithium based grease, the ordinary multipurpose grease of today, technically NLGI consistency grade 2. That is long standing classic car practice for chassis and suspension nipples of this era, and Castrol LM is one commonly used example among many equivalents.

What the archive cannot tell you is that AC specified it. The only period product name anywhere in the source discussion is Duckhams LB 10, a lithium general purpose grease, and that comes from one owner reading the chassis plate of an AC 428, a later and entirely different car. His own words were that he could not imagine an Ace being any different. That is a reasonable assumption and it may well be right, but it is an assumption about another model, and this archive will not print it as an Ace specification.

One type to avoid

General classic practice, rather than anything the archive can trace to AC, is to keep molybdenum disulphide grease, the moly or constant velocity joint type, away from ordinary suspension grease points, and to use a plain multipurpose lithium grease instead. Some specific components have their own needs: a steering rack, for example, may want a softer, flowable grease rather than the stiffer chassis type. Check your chart if you have one, or ask a specialist.

Greasing technique, briefly

Work methodically around all the nipples, front and rear suspension, and the steering, to the schedule in the lubrication chart. Wipe each nipple clean first, then pump fresh grease until it just shows at the joint. If a nipple will not take grease, do not force it: it may be blocked, or the joint seized, which is worth investigating.

Blocked nipples and seized joints

A nipple that refuses grease is the most common frustration on a car that has stood. The first rule is not to force it with the gun: high pressure can rupture the seal or blow the grease path past the part that actually needs lubrication. Start with a firm but gentle push on the grease-gun coupler; if resistance is hard, stop.

• Clean the nipple first. Remove the cap if fitted, then wipe away old grease and road dirt. A small brush and a solvent such as paraffin or WD-40 on a rag will clear the head and the ball-check inside. Compressed air can help, but wear eye protection and do not force grit into the joint.
• Check the coupler fit. A loose or damaged gun coupler will not seal, so it leaks around the nipple instead of pushing grease through. A four-jaw hydraulic coupler is the most reliable on old, worn nipples.
• Try a thin oil first. A few drops of penetrating oil left to soak for a few hours can clear the narrow passage. Tap the joint very lightly with a soft drift while the oil is soaking; vibration helps the oil move. Then wipe the nipple and try fresh grease again.
• Recognise a seized joint. If the part still will not take grease after cleaning, the pin or trunnion may be seized. A seized king-pin or trunnion is a safety issue, not a service nuisance, the assembly needs dismantling, inspection and probably renewal. Stop here and seek a specialist.

Regular greasing is the only way to avoid this situation: fresh grease keeps the passages open and the joints free. Once a nipple is blocked, the time saved by forcing it is quickly lost in the damage it can cause.

What is not established

• What grease AC specified for the Ace or Aceca. The question was asked on the club forum and nobody answered it.
• Whether an Ace or Aceca chassis plate or handbook names a grease at all. The archive has not seen one that does.
• Whether the Duckhams LB 10 named on an AC 428 chassis plate applies to the Ace and Aceca. The owner who reported it said himself that he was assuming, and the 428 is a different car of a later period.

In short

The archive does not know what AC specified for the Ace and Aceca suspension grease points, and says so rather than filling the gap. What owners use is a multipurpose lithium grease of NLGI grade 2, which is ordinary classic car practice for a chassis of this era. Read your own lubrication chart or plate if your car has one, avoid moly grease on these joints, treat a steering rack separately, and if you find a factory figure the archive would like to know.

Sources. This article draws on a thread on the AC Owners' Club forum of March 2025 in which an owner asked which grease the Ace suspension takes and no answer specific to the Ace was given. The only product named in it, Duckhams LB 10, was read from the chassis plate of an AC 428. The grease type described here is general classic car practice rather than an AC specification, and is marked as such throughout. No individual member is named.

A general guide to greasing the suspension and chassis, not a substitute for your handbook's lubrication chart, your chassis plate, or a specialist. Product names change, match by type where the original is obsolete, avoid moly grease on these joints, and confirm anything to do with steering or safety with a specialist.